Can someone explain how fold mountains are formed ? ?

Fold mountains are mountains that form mainly by the effects of folding on layers within the upper part of the Earth's crust. hope it helps

The earths structure is made by plates, some of the underwater, some of them on land. these plates move in all different directions, and some of the borders of plates are called collision zones, because in some cases 2 plates will crash together. because of the fact continental (on land) plates are the same density, when they crash together, they will both rise, creating fold mounains

hope this helps :)

Answer (d) may increase or decrease porosity through dissolution or deposition;