Ans. c (Complete extension) (Ref. Park Textbook of PSM 22nd/pg.635)A family is a primary unit in all socities. Familes are not constant. A normal family-cycle is generally conceived as having six phases as follows:BASIC MODEL OF NUCLEAR FAMILY LIFE CYCLE Phase of family cycleCharacterizing EventsNo.DescriptionBeginning of phaseEnd of phaseIFormationMarriageBirth of 1st childIIExtensionBirth of 1st childBirth of last childIIIComplete extensionBirth of last child1st child leaves homeIVContraction1st child leaves homeLast child has left home of parentsVCompleted contractionLast child has left home of parents1st spouse diesVIDissolution1st spouse diesDeath of survivor (Extinction)