To automate the process of sending an email notification to the customer when a support rep at Ursa Major Solar closes a case, the following settings should be used:
* Case Close Template in the Support Settings: This feature allows the administrator to define a standard email template that will be automatically sent to the contact associated with the case when it is closed. This ensures consistency in communication and reduces the manual effort required by the support reps.
* Notify Contact Checkbox on Close Page Layout: Adding this checkbox to the case close page layout gives the support reps the option to send an email notification to the contact when closing a case. If the checkbox is checked, the email notification (defined by the case close template) will be sent.
The other options, B (Auto response rule step set 'or status of closed') and D (Add the Knowledge component to the closed layout), do not directly address the requirement of sending an email notification when a case is closed.
References:
* Salesforce Help: Automate Case Management
* Salesforce Help: Case Support Settings

To require the Amount field during the negotiation stage for sales users but allow their managers to make changes, the administrator should configure a validation rule that checks if the user profile is not a sales manager, the stage is negotiation, and the amount is blank. This will prevent sales users from saving the record without entering an amount, but allow sales managers to do so. Making the field required for all users will not meet the requirement. Creating a formula field or assigning the administrator profile to the managers will not affect field requirement. References: https://help.salesforce.com/s/articleView?id=sf.
validation_rules_overview.htm&type=5

A sales process is a set of stages that an opportunity goes through as it moves from creation to close. It can be customized by administrators to match different business models or product lines within an org. Creating a new sales process can help Dreamhouse Realty define a different set of stages for its new home concierge offering that is unlike anything the company has offered in the past and follows a different business model.
Creating a quick action, a new approval process, or a new opportunity product are not solutions for creating a customized sales process; they are used for different purposes such as creating records, approving records, or adding products to opportunities. References: https://help.salesforce.com/s/articleView?id=sf.
customize_salesprocess.htm&type=5

To track shoe designs by products, prevent them from being deleted, and allow multiple designs for one product across various stages, the administrator should create a custom object for shoe designs and configure a custom lookup field for shoe designs on the Product object. This will create a one-to-many relationship between products and shoe designs, and allow users to link multiple shoe designs to one product record. To prevent shoe designs from being deleted, the administrator can use validation rules or permissions. Adding a custom master-detail field for shoe designs on the Product object will create a many-to-one relationship, which is not desired. Using the standard object for designs or configuring a validation rule will not meet the requirement. References: https://help.salesforce.com/s/articleView?id=sf.
customize_object_relationships_overview.htm&type=5

Field update and email alert are two types of automated actions that can be added as part of the approval process. Field update allows you to change the value of a field on a record when it is submitted, approved, rejected, or recalled. Email alert allows you to send an email to one or more recipients when a record is submitted, approved, rejected, or recalled.
References: https://help.salesforce.com/s/articleView?id=sf.approvals_automated_actions.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.approvals_creating_approval_actions.htm&type=5