An agreement which is enforceable by law at the option of one or more of the parties thereto, but not at the option of the other or others, is a

A. Invitation to offer B. Counteroffer C. Communication D. None of these

A. Is available to Y's representatives alone B. Is available to Z alone C. Is available to Y's representatives & Z both D. Is available to Y's representatives & after the death of Z, his representatives

A. Theory of unjust enrichment B. The right of lien C. Test of agency D. Doctrine of frustration

A. The active concealment of a fact by one having knowledge or belief of the fact B. A promise made without any intention of performing it C. The suggestion, as a fact, of that which is true, by one who does believe it to be true D. None above