4. The case of Kepong Prospecting Ltd v A.E. Schmidt & Marjorie Schmidt [1968] 1 MLJ 170 laid down the principle that

A.A consideration is executed when a promise is made in exchange for the performance of an act

B.A consideration given in the past is valid consideration

C. A contract without consideration is voidable

D. A promise made by one party in return for a promise made by another party is known as an executory consideration