What Is the Source of the Fine, Powdery Dust Found

Multiple Choice

What is the source of the fine, powdery dust found on the Moon's surface?

A) it is sand, produced in exactly the same way sand is produced on the Earth's beaches
B) it is the result of volcanic activity on the Moon over billions of years
C) it is the result of many impacts, breaking surface rocks apart over billions of years
D) it is the result of gas bubbling up from inside the Moon, which chemically changes the surface soil
E) even though the astronauts brought home lots of samples of Moon dust, we have no idea why there is such a layer on the Moon's surface