Answer:
C.Implied warranty
Step-by-step explanation:
An implied warranty is an assumed assurance that the product purchased is fit to function as intended. The implied warranty can be oral, written, or silent.
An implied warranty protects customers from dishonest traders. All products and some services carry an implied warranty, written or not. The warranty guarantees that the product conforms to the buyer's expectations. For example, if you buy a car, you expect the engine to start and the vehicle to move.
Frank has an implied warranty. He's expectations are the blind will work. Products with an implied warranty may also come with other forms of assurances such as express or full warranties.