The correct answer is A. Could have forgotten
Explanation:
A verb phrase includes a regular verb, along with auxiliary verbs, modal verbs or any other verb forms. This implies in a verb phrase you can find regular verbs such as cook, write, jump; auxiliary verbs such as have, do, be and modal verbs such as might, should or could.
According to this, in the sentence "Could you have forgotten your sunglasses in the car?" the complete verb phrase is "could have forgotten" because this includes the main verb "forgotten" (present perfect of forget) along with the auxiliary verb "have" and the modal verb "could". Also, in this case, other sections of the sentence such as "you" or "your sunglasses" are not part of the verb phrase because these are not verbs or verb forms.
