While walking on the desert, you found outer layers of a rock peeled away like an onion. Which of the following factor is responsible for this phenomenon?

The correct option is B Temperature
Rocks expand in daytime due to exposure to harsh sunlight and high temperature. When the temperature falls down rapidly at night, rock contracts. The outer, exposed layer expands and contracts more than the inside of the rock. This results in stress on the rock, and over a period of time, with continuous stress and pressure, the outer surface of the rock begins to develop cracks and tend to ‘peel away’ layer by layer, like the layers of an onion.