Question: What election did Varaprasad Rao Velagapalli win to constitute the 16th Lok Sabha, electing members of parliament for all 543 parliamentary constituencies of India?  
Sentence (from "12th Lok Sabha"): Atal Bihari Vajpayee became the 16th prime minister of India but government lasted only about 13 month due to not clear mandate and the party was not able to get support from other parties, after withdraw of support by AIADMK.
Relevant evidence: No