The correct option is A A period not exceeding one year at a time and not extending in any case beyond a period of six months after the proclamation has ceased to operate
The term of the Lok Sabha, unless dissolved earlier, is five years from the date appointed for its first meeting. However, while a proclamation of emergency is in operation, this period may be extended by Parliament by law for a period not exceeding one year at a time, and not extending in any case, beyond a period of six months after the proclamation has ceased to operate. Fourteen Lok Sabhas have been constituted so far. Hence, Option A is correct. The rest of the stipulated periods are not applicable to Lok Sabha, so, incorrect.