What is the best definition of a passive verb?
A. With a passive verb, the subject receives the action.
B. With a passive verb, the subject performs the action.
C. With a passive verb, the action is slow-moving.
D. Passive verbs indicate lazy subjects.

Hint: A verb, from the Latin verbum meaning word, is a word that in syntax conveys an action, an occurrence, or a state of being. In passive voice the subject is subjected to the actions performed by the object in the sentence.

Complete answer:
Now let us look into the given options:
Option A. With a passive verb, the subject receives the action- this statement is correct in regards to passive verbs as the passive verb indicates that the action or work is being performed on the subject. When the sentence's subject receives the verb's action, the sentence is written in the passive voice.The subject in active voice performs the action of the verb in the sentence. The subject is acted upon by another performer of the verb in the passive voice.
Option B. With a passive verb, the subject performs the action- this statement is incorrect and can not be used as the definition of passive verbs because passive verbs indicate that the action or work is being performed on the subject. The subject never performs the action when the passive verb is used.
Option C. With a passive verb, the action is slow-moving - this statement is incorrect as passive verb does not mean that the subject in the given sentence is literally ‘passive’, meaning not very active in its movement. Passive verbs have nothing to do with the movement of the subject; it only indicates that action is being performed on the subject.
Option D. Passive verbs indicates lazy subjects.This statement is incorrect as passive verbs have nothing to do with the laziness of the subject; it is used to indicate that the action is being performed on the subject.

Thus the correct answer is option (A) as it is the best definition of a passive verb.

Note: A sentence with active voice has a subject who acts on the verb. A subject is a beneficiary of a verb's action in passive voice. Hence, when the action or work is being performed on the subject then the sentence is a passive voice.