A huge radio telescope in Puerto Rico that has played a key role in astronomical discoveries, collapsed in December 2020. When was the telescope built?

A huge radio telescope in Puerto Rico that has played a key role in as

1.	A huge radio telescope in Puerto Rico that has played a key role in astronomical discoveries, collapsed in December 2020. When was the telescope built?
A.	1940s
B.	1950s
C.	1960s
D.	1970s
E.	1980s
Answer» D. 1970s