The sentence has been given in the Active/Passive voice. From the given options, choose the one which best expresses the given sentence in the Passive/Active voice.

 One should keep one’s promise.

A sentence's activity can be depicted in two ways: active and passive voice.

Regardless of tense, the passive voice always utilizes the past participle form of the verb as the main verb. Only the auxiliary verbs are affected by the active voice in the sentence. The placement of the actor (subject) and the activity might help you determine if a sentence is in active or passive voice (verb). The active voice is used when the actor—who may be a person or an object—comes before the action in a sentence.

Option D) is valid since the given sentence's subject becomes the object and vice versa. The main verb (keep) is also employed in the third form (kept).

Option A, B, and C are incorrect since 'us' is not required, 'has to' cannot be used, and 'keeping' is not a past participle form of the primary verb.