Astronauts Deployed a Solar Wind Measuring Experiment on the Moon

Astronauts deployed a solar wind measuring experiment on the Moon because

A) the lunar surface is protected by an atmosphere.
B) there is no electromagnetic energy arriving there.
C) the experiment would not work if deployed at Earth's surface due to protective aspects of Earth's atmosphere.
D) the Moon is closer to the Sun,so it is easier to measure the effect of solar wind.
E) there is no solar wind arriving at the lunar surface.