Jane Looked After Colin's Dog in February

Jane looked after Colin's dog in February. In May, Jane went away and asked Colin, in return, to look after her cat. Colin refused. Did Colin breach a contract?

A) Yes, the consideration does not have to be monetary.
B) Yes, the consideration was of value.
C) Yes, Jane was entitled to reciprocal treatment under the law of equity.
D) Yes, the intention was that the services would be reciprocated.
E) No, past consideration is not valid.