Where both the parties are under mistake as to matter of fact, the contract under section 20 is

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