Correct option is C
Bentonite:
It is a chemically weathered volcanic ash. It is also not suitable for construction purposes.
Loam:
Loam is the ideal soil type, usually, it is a combination of sand, silt, and clay. It is dark in color and soft, dry, and crumbles to the touch. Loam is great for supporting foundations because of its evenly balanced properties, especially how it retains water at a balanced rate. It is the best soil for construction purposes.
Peat:
A highly organic soil, consisting almost entirely of vegetative matter in varying states of decomposition, brown to black in color, possessing an organic odour (odor). Peat is fibrous and highly compressible. It is not suitable for construction purposes.
Humus:
A dark brown organic, amorphous earth of topsoil, consisting of partially decomposed vegetative matter. It is not suitable for construction purposes
