What Did the Magellan Spacecraft Tell Us About Venus' Upper

What did the Magellan spacecraft tell us about Venus' upper atmosphere,before the spacecraft burned up on entry into the atmosphere?

A) The upper atmosphere is unexpectedly uniform compared to that of Earth.
B) The temperature of the upper atmosphere increases unexpectedly to over 1000 K.
C) The upper atmosphere is almost saturated with water vapor.
D) The density of Venus' upper atmosphere varies markedly from one place to another.