What does the word "discount" (Par

A．Forms of life on the other planets don't evolve to intelligent beings.
B．Earth is the only planet that contains life in the universe.
C．Life on the other planets destroys itself
D．Beings from outer space are too far away from us.

A．a more advanced civilization will destroy us if they visit us at present
B．the original inhabitants of America were better off because of Columbus' visit
C．being visited by a more advanced civilization will do us good
D．we wouldn' t be better off even though we were visited by the beings from outer space at present