To return all artifacts that contain a SHA1 file hash using the Splunk SOAR REST API, the correct query would use the _filter_cef_Shal_contains parameter. This parameter filters the artifacts to only those that contain a value in the SHA1 field within the Common Event Format (CEF) data structure. The contains operator is used to match any artifacts that have a SHA1 hash present1.
References:
Understanding artifacts - Splunk Documentation

Explanation
The correct answer is B because the format block can be used to generate HTML or CSS content for output in email messages, user prompts, or comments. This can be useful for creating rich and interactive content for communication and collaboration purposes. The answer A is incorrect because the format block cannot be used to generate arrays for input into other functions, as the format block only outputs strings. The answer C is incorrect because the format block cannot be used to generate string parameters for automated action blocks, as the format block only outputs strings. The answer D is incorrect because the format block cannot be used to create text strings that merge static text with dynamic values for input or output, as the format block only outputs strings. Reference: Splunk SOAR Playbook Development Guide, page 35.

Explanation
The Phantom API command to create a custom list is phantom.create_list(). This command takes a list name and an optional description as parameters and returns a list ID if successful. The other commands are not valid Phantom API commands. phantom.add_list() is a Python function that can be used in custom code blocks to add data to an existing list. Reference, page 5.