Answer:
a. an express warranty.
Step-by-step explanation:
An express warranty -
It is the insurity given by the seller in order to give the replacement or repairs for any of the faulty product or services , within a particular time frame after purchasing the product , is known as an express warranty .
It helps to make sure about the product the buyer have purchased and for any repairs in the future .
Hence , from the question , the example shown is about an express warranty .