A. During festival people throng the shops.
B. Men, women and children throng the shops before festival making various purchases.
C. Men, women and children make purchases during festivals.
D. The shops are thronged by people making purchases.
Given sentence is in Passive voice and in Present Simple Tense. We need to change it into active voice. While changing the voice objects becomes subject and subject changes into object.
Subject + V1 + Other agents.