Study the following statements and identify the correct combinations of statements.

Statements:

(A): Laterites are residual soils formed in tropical regions. They are very soft when freshly cut but become hard after long exposure. Hardness is due to the cementing action of iron oxide and aluminium oxide

(B): hardpans is a type of soil that contains gravel, sand and silt. The particles are cemented by calcium carbonate.

(C): caliches are sedimentary deposits consisting of alternate thin layers of silt and clay. The thickness of each layer seldom exceeds 1 cm. These clays are the results of deposition in lakes during periods of alternately high and low waters.

(D) Loam is a mixture of sand, silt and clay. The term is generally used in agronomy. The soil is well suited to tilling operations