The Existence of the Great Red Spot of Jupiter Has

Multiple Choice

The existence of the Great Red Spot of Jupiter has been known since

A) the arrival at Jupiter of Voyager 1, with its imaging cameras, in 1979.
B) the time of Hooke and Cassini in the 1600s.
C) first light at the 200-inch telescope on Mount Palomar, in 1948.
D) the first flyby of a spacecraft, Pioneer 10, in December 1973.