(a) Generally the contract of a minor is voidable. If in a contractual transaction a minor receives property or other valuable consideration and, after arrival at the age of majority, retains possession of such property or continues to enjoy the benefit of such other valuable consideration, he shall have thereby ratified or affirmed the contract and it shall be binding on him.

(b) The contract of a minor for necessaries shall be binding on him as if he were of legal majority except that the party furnishing them to him must prove that the parent or guardian of such minor had failed or refused to supply sufficient necessaries for him.