Why aren't frescoes affected by moisture?

A.

because the paint dries with the plaster on the wall, effectively making the fresco part of the wall

B.

because the mixing agent used in fresco is glue, which repels moisture

C.

because they are painted on wet plaster, so the paint already absorbs all the moisture it can

Question:why aren't frescoes affected by moisture?

A.

because the paint dries with the plaster on the wall, effectively making the fresco part of the wall

B.

because the mixing agent used in fresco is glue, which repels moisture

C.

because they are painted on wet plaster, so the paint already absorbs all the moisture it can

*Answer_is because the paint dries with the plaster on the wall, effectively making the fresco part of the wall

I think A is the answer.