To add components to the utility bar of an existing app:
* C. App Manager. This is where Salesforce apps are configured, including the utility bar which can house components like a chat tool, recent items list, or custom Lightning components.
Steps to edit an app's utility bar:
* Navigate to Setup # App Manager.
* Locate the desired app and click on the dropdown next to it # select Edit.
* In the App Builder, navigate to the Utility Items tab.
* Click 'Add' to include new components to the utility bar.
* Configure the properties of the utility item as needed.
* Save the app configuration.
For step-by-step instructions on modifying apps, see Salesforce's guide on Managing Apps in Lightning Experience.

The app builder should use three features to meet the business requirements:
* Process Builder: This is a type of automation tool that can execute actions based on certain criteria. In this case, the process builder can have a criteria that evaluates if an opportunity is in the Secure Commitment Stage, and then execute an action that submits it for approval.
* Apex: This is a programming language that allows developers to execute complex logic on the Salesforce platform. Apex can be used to create triggers that run before or after certain events, such as insert, update, delete, or undelete of records. In this case, Apex can be used to create a trigger that runs before an opportunity is updated and submits it for approval if it is in the Secure Commitment Stage.
* Flow: This is another type of automation tool that can guide users through a series of screens and perform actions based on user input. Flow can also be triggered by certain events, such as when a record is created or updated. In this case, Flow can be used to create a record-triggered flow that runs after an opportunity is updated and submits it for approval if it is in the Secure Commitment Stage.
Option A and D are not features that can meet the business requirements.

Create a page layout with the field and use field-level security to hide the field from all other users is how the app builder should meet the requirement of making the comment field on Review private to anyone outside of HR department. Field-level security can control which profiles can view or edit a field on a record. Create an Apex sharing rule, create a sharing rule to share the field with VP of HR with Role and Subordinates, and create a page layout with the field for HR users and another page layout without the field for all other users are not valid or feasible solutions for this requirement.

Groups is available in the Chatter section of the navigation menu, not in the selected list for the navigation menu. According to the Salesforce documentation, "Groups appear in Chatter, not in Navigation Menu." Groups is not available in the recent section of the navigation menu, nor is it included in the Smart Search items but unavailable on the navigation menu. Groups is unavailable in the selected list for the navigation menu.

Roll-up summary fields can only be created on master-detail relationships, and they can only calculate numeric fields, such as currency, percent, and number. Date and time fields are not supported for roll-up summary fields. Checkbox fields can be used in roll-up summary filters, but not in the field to aggregate