The correct Active/Passive form of the given sentence is:

☀ Have his instructions been carried out by them?

Explanation for other options:

☀ Have his instructions were carrying out by them? This option is not in the correct passive voice. It uses the active voice "were carrying out," which is not the correct form for the passive construction. The correct form should be "have been carried out."

☀ Have their instructions been carried out by others? This option changes the possessive pronoun "his" to "their" and adds "by others" as the agent performing the action. While this form is grammatically correct, it changes the meaning of the sentence by using a different possessive pronoun and agent.

☀ Had been his instructions been carried out by them? This option uses the past perfect tense ("had been carried out"), which suggests an action completed before a certain point in the past. The original sentence uses the present perfect tense ("have carried out"), indicating a present or recent action. The correct form should use the present perfect tense, as shown in the correct option.