What was the communist reaction to people fleeing east germany? a. a ban on all travel b. declaring war on west germany c. building the berlin wall d. reuniting germany

Best answer is A) A ban on all travel. 

The tempting answer is "building the Berlin Wall", but the Soviets actually instituted a travel ban in response to people leaving westward in 1956, 5 years before construction of the wall began in 1961, 

This answer would be c