The correct options are
A The rainwater penetrates the rocks and loosens the particles of the rock.
C This process works on rocks which are formed by the clustering of sand particles due to high pressure.
Granular weathering works on rocks which are formed because of the clustering together of sand particles. Some examples of such rocks are sandstone and conglomerate. When it rains heavily, water penetrates these rocks, and the particles of the rock get loosened and get separated from the main rock. Eventually, it turns the rock into a granular substance.