For this question, our job is to find the necessary assumption the argument is relying on. We’re told about how a policy at a department store works, and then are told that by the same standard, Bingham’s jewelry store should give the consumer a refund. The terms for the policy were:
1. If you buy a watch at a department store and use it only in the way it was ended to be used 2. If it stops working the next day
.....then, the department store will refund your money.
That’s the standard we’re told should be used to justify that our consumer should get a refund at Bingham’s jewelry, even though Bingham’s is not a department store. But, does our consumer even meet those criteria? He says the watch he bought from them stopped working the very next day. That’s only the second criteria, however. To conclude if he should get a refund by the same standard set forth by the department store, you would also need to know he met the first criteria, too.
That reasoning is what makes D correct. For E, the argument is not relying on the assumption that the watch is new or old. We weren’t given any criteria in the policy that was related to that. So, this is irrelevant!