Answer:
I think it is either A or D
True. A nuclear family includes a couple and their dependent children. Now a days there are many types of families like single parent families, extended families, childless families, step families, etc.
The Paleozoic Era is bracketed by two major events in earth's history. It began with an unexplained explosion in animal life and ended with the world's largest mass-extinction known to man. The causes of these great events are currently unknown and under debate.
