Explanation
The correct answer is B, because an HTTP header field is an intended use of HTTP Event Collector tokens. An HTTP Event Collector token is a unique identifier that is used to authenticate and authorize data sent to Splunk via the HTTP Event Collector (HEC). An HEC token can be specified in the Authorization header field of the HTTP request, using the format Authorization: Splunk <token> 2. The other options are incorrect because they are not valid ways to use an HEC token. A cookie is a small piece of data stored by the web browser, not by Splunk. A JSON field in the HTTP request is used to specify the event data or metadata, not the HEC token. A password in conjunction with login is not related to HEC, but to Splunk Web or REST API authentication.

Explanation
The correct answer is A because the tstats command is a generating command. A generating command is a type of command that does not require a base search and can generate results from the summary data or the raw data. The tstats command is a generating command that can retrieve statistical information from the summary data, such as the accelerated data models or the data model summaries. The tstats command is similar to the stats command, but it is faster and more efficient, as it does not need to scan the raw data. The other options are incorrect because they are not the type of command that tstats is. Option B is incorrect because a transforming command is a type of command that converts the results into a data table with rows and columns. Option C is incorrect because a centralized streaming command is a type of command that processes the results on the search head, not on the indexers. Option D is incorrect because a distributable streaming command is a type of command that processes the results on the indexers, not on the search head.
You can find more information about the tstats command and the types of commands in the Splunk Developer Guide.

Explanation
The correct answer is A, because data can be added to a KV Store collection only in JSON format. KV Store is a feature that allows Splunk to store and manage data in collections of key-value pairs. A KV Store collection is a logical grouping of key-value pairs that can be accessed and manipulated by Splunk apps. Data can be added to a KV Store collection either by using the Splunk Web interface, the Splunk REST API, or the Splunk SDKs. In all cases, the data must be formatted as JSON objects, which are collections of name-value pairs enclosed in curly braces1. The other formats, such as XML, CSV, and TXT, are not supported by KV Store.