"If a party to a contract, aware of a breach going to the root of the contract, or of other circumstances entitling him to terminate the contract, though unaware of the existence of the right to terminate the contract, exercises rights under the contract, he must be held to have made a binding election to affirm. Such conduct is justifiable only on the footing that an election has been made to affirm the contract; the conduct is adverse to the other party and may therefore be considered unequivocal in its effect. The justification for imputing to the affirming party a binding election in these circumstances, though he be unaware of his alternative right, is that, having a knowledge of the facts sufficient to alert him to the possibility of the existence of his alternative right, he has acted adversely to the other party and that, by so doing, he has induced the other party to believe that performance of the contract is insisted upon. It is with these considerations in mind that the law attributes to the party the making of a choice, though he be ignorant of his alternative right. For reasons stated earlier the affirming party cannot be permitted to change his position once he has elected."