Why Has It Been So Difficult to Examine the Surface

Multiple Choice

Why has it been so difficult to examine the surface of Venus with unmanned probes?

A) The atmosphere is so cloudy that it interferes with radio wave signals from earth,making communication with a probe difficult.
B) The Venesian magnetic field is so strong it destroys electronics on the probes.
C) Solar radiation is so intense that probes are lost before they reach Venus.
D) The air pressure at the surface is equivalent to a water depth of nearly 1km on Earth,and temperatures are very high,which tends to destroy the probes.