Fill in the blank with the most appropriate word.
Someone heard him shout for help. He __________ shout for help.
An action in a sentence can be represented in two ways, namely active and passive voice.
The passive voice always uses the past participle form of the main verb irrespective of any tense. Only the auxiliary verbs depend upon the sentence given in active voice.
The correct answer is D)was heard to
The option D is correct as the given sentence is in active voice and to transform it into passive voice the subject of the given sentence
(someone) comes in the place of the object(him- though someone can be neglected here ) and vice versa. Also, as the sentence is in the simple past tense, 'heard' is added after the helping verb 'was' and before to.
Options A, B, and C are wrong as has been , is, and was can not be used here.