In 1961, East Germany: a. erected a wall between East and West Berlin to stop the mass exodus of East Germans to West Berlin.
b. stop the movement of large numbers of West Germans to East Berlin.
c. halt the flow of overpriced goods from West Berlin to East Berlin.
d. protect East Berliners from U. S. troops stationed in the western part of the city.

(A)It sent troops into West Berlin to arrest people who were against communism.

Explanation:

answer; /// the correct answer is evidence of the olmec civilization has been found in southern american in a hot steamy forest, archaeologists have found earthen artifacts at several sites that were evidence of the olmec civilization. these   artifacts were mounds,courtyards and pyramids build of stones, also on top of the mounds were many monuments made of stone, some of these stone structures are very large, they weigh as much as 44

to act quickly in times of danger to the united states

because you have to act quickly if you want to live/survive.