The search string below returns events from the data model named Application_State.
| datamodel Application_State All_Application_State search
The search string does the following:
It uses the datamodel command to access a data model in Splunk. The datamodel command takes two arguments: the name of the data model and the name of the dataset within the data model.
It specifies the name of the data model as Application_State. This is a predefined data model in Splunk that contains information about web applications.
It specifies the name of the dataset as All_Application_State. This is a root dataset in the data model that contains all events from all child datasets.
It uses the search command to filter and transform the events from the dataset. The search command can use any search criteria or command to modify the results.
Therefore, the search string returns events from the data model named Application_State.

The correct answer is B. Delimiters. This is because the delimiters method is designed for structured event data, such as data from files with headers, where all of the fields in the events are separated by a common delimiter, such as a comma or space. You can select a sample event, identify the delimiter, and then rename the fields that the field extractor finds. You can learn more about the delimiters method from the Splunk documentation1. The other options are incorrect because they are not suitable for comma-separated data. The regular expression method works best with unstructured event data, where you select and highlight one or more fields to extract from a sample event, and the field extractor generates a regular expression that matches similar events and extracts the fields from them. The eval expression is a command that lets you calculate new fields or modify existing fields using arithmetic, string, and logical operations. The table extraction is a feature that lets you extract tabular data from PDF files or web pages. You can learn more about these methods from the Splunk documentation23 .

The correct answer is C. _time.
The timechart command creates a time series chart with corresponding table of statistics, with time used as the X-axis1. You can specify a split-by field, where each distinct value of the split-by field becomes a series in the chart1. In this case, the split-by field is action, which means that the chart will have different lines for different actions, such as accept, reject, or fail2. The count function will calculate the number of events for each action in each time bin1.
For example, the following image shows a timechart of the count by action for a similar search3:
As you can see, the x-axis is populated by the _time field, which represents the time range of the search. The y-axis is populated by the count function, which represents the number of events for each action. The legend shows the different values of the action field, which are used to split the chart into different series.
Reference:
2: Timechart Command In Splunk With Example - Mindmajix 1: timechart - Splunk Documentation 3:
timechart command examples - Splunk Documentation

Data model acceleration is a feature that speeds up searches on data models by creating and storing summaries of the data model datasets1. To enable data model acceleration, you must have administrative permissions or the accelerate_datamodel capability1. Therefore, option D is correct. Accelerated data models cannot be edited unless you disable the acceleration first1. Therefore, option B is correct. Private data models cannot be accelerated because they are not visible to other users1. Therefore, option C is correct. Root events can be accelerated as long as they are not based on a search string1. Therefore, option A is incorrect.

Reference: https://answers.splunk.com/answers/653427/fillnull-doesnt-work-without-specfying-a-field.html The fillnull command is a search command that replaces null values with a specified value or 0 if no value is specified. Null values are values that are missing, empty, or undefined in Splunk. The fillnull command can replace null values for all fields or for specific fields. The fillnull command can take an optional argument called value that specifies the value to replace null values with. If no value argument is specified, the fillnull command will replace null values with 0 by default.