Which of the following geological processes adds new rock to the surface of the earth?
a) volcanic activity
b) glacial activity
c) soil erosion
d) weathering

A) Volcanic activity

Explanation: Volcanic activity which includes volcanic eruptions is a high temperature process through which rocks such as metamorphic rock melts through large scale earth movements and transportation its it's Magma materials into another location adding new rocks.

Volcanic activity is a geological process which add new rocks to the Earth,the other options involved breakdown processes which doesn't add new rocks.

Glacial activity involves the melting of ices due to high temperature.

Soil erosion is the movement of soil particles caused by mainly by water movement,air etc.

Weathering is the breakdown of rocks into small pieces.

fertilization is the union of an egg and a sperm cell i believe.