An event type in Splunk is defined by a search string that returns a specific set of events. The search string index=games sourcetype=score player=* score>9999 is valid because it filters events based on specific criteria directly within the main search command. This search will find all events in the games index with a sourcetype of score, where the player field exists, and the score is greater than 9999. This specificity and direct filtering make it suitable for defining an event type.
Reference:
Splunk Docs: Create event types

The correct answer is B. Reusable pieces of search processing language.
The explanation is as follows:
Search macros are knowledge objects that allow you to insert chunks of SPL into other searches12.
Search macros can be any part of a search, such as an eval statement or a search term, and do not need to be a complete command12.
You can also specify whether the macro field takes any arguments and define validation expressions for them12.
Search macros can help you make your SPL searches shorter and easier to understand3.
To use a search macro in a search string, you need to put a backtick character () before and after the macro name[^1^][1]. For example, mymacro`.

where 10yearAnnerversary=Renewal-MonthYear.
The where command is used to filter the search results based on an expression that evaluates to true or false. The where command can compare two fields, two values, or a field and a value. The where command can also use functions, operators, and wildcards to create complex expressions1.
The syntax for the where command is:
| where <expression>
The expression can be a comparison, a calculation, a logical operation, or a combination of these. The expression must evaluate to true or false for each event.
To compare two fields with the where command, you need to use the field names without any quotation marks. For example, if you want to find events where the values for the 10yearAnnerversary field match the values for the Renewal-MonthYear field, you can use the following syntax:
| where 10yearAnnerversary=Renewal-MonthYear
This will return only the events where the two fields have the same value.
The other options are not correct because they use quotation marks around the field names, which will cause the where command to interpret them as string values instead of field names. For example, if you use:
| where '10yearAnnerversary'='Renewal-MonthYear'
This will return no events because there are no events where the string value '10yearAnnerversary' is equal to the string value 'Renewal-MonthYear'.
Explanation:
The correct answer is
Reference:
where command usage

As mentioned before, a calculated field is a field that you create based on the value of another field or fields2. A calculated field can be based on extracted fields, which are fields that are extracted from your raw data using various methods such as regular expressions, delimiters or key-value pairs2. Therefore, option B is correct, while options A, C and D are incorrect because they are not types of fields that a calculated field can be based on.

The correct answer is A. startswith.
The explanation is as follows:
The transaction command is used to find transactions based on events that meet various constraints12.
Transactions are made up of the raw text (the _raw field) of each member, the time and date fields of the earliest member, as well as the union of all other fields of each member1.
The startswith option is used to define the first event in a transaction by specifying a search term or an expression that matches the event13.
For example, | transaction clientip JSESSIONID startswith="view" will create transactions based on the clientip and JSESSIONID fields, and the first event in each transaction will contain the term "view" in the _raw field2.