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 B)Men, women, and children throng the shops before festivals making various purchases.
The option B is correct as the given sentence is in the passive voice and to transform it into the active voice, the subject of the given sentence (the shops) comes in the place of the object(men, women, and children) and vice versa. Also, as the sentence is in the simple present tense, the first form of the verb (throng) is used.
Options A, C, and D are wrong as the sentence is not structured correctly, the object is missing, and the subject is not in its place respectively.