There is a global search named “global_search” defined on a form as shown below:index-_internal source-*splunkd.

The correct answer is C and D because these are the valid post-processing searches. A post-processing search is a type of search that applies additional filters or transformations to the results of a base search. A post-processing search can use any SPL command that does not require access to the raw data, such as stats, search, eval, and chart. Option C is correct because it uses the stats command to aggregate the count by log level. Option D is correct because it uses the search command to filter the results by log level and then uses the stats command to aggregate the count by component. Option A is incorrect because it uses the tstats command, which is not a valid post-processing command, as it requires access to the raw data. Option B is incorrect because it uses the sourcetype field, which is not available in the results of the base search, as it only returns the component and log_level fields. You can find more information about the post-processing searches in the Splunk Developer Guide.