The correct answer is B. Root event dataset. This is because root event datasets are defined by a constraint that
filters out events that are not relevant to the dataset. A constraint for a root event dataset is a simple search that
returns a fairly wide range of data, such assourcetype=access_combined. Without a constraint, a root event
dataset would include all the events in the index, which is not useful for data modeling.You can learn more
about how to design data models and add root event datasets from the Splunk documentation1. The other
options are incorrect because root transaction datasets and root search datasets have different ways of defining
their datasets, such as transaction definitions or complex searches, and root child datasets are not a valid type
of root dataset.

The correct answer is A. | 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'.
References:
* where command usage

Explanation/Reference: https://docs.splunk.com/Documentation/Splunk/8.1.1/Knowledge/SetupaPOSTworkflowaction

The descriptions of the data models that come with the Splunk Common Information Model (CIM) Add-on are documented in the CIM Add-on manual (Option B). This manual provides detailed information about the data models, including their structure, the types of data they are designed to normalize, and how they can be used to facilitate cross-sourcing reporting and analysis.

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.