Question

accessories not installed by the original equipment manufacturer (oem) can be difficult to diagnose for all of the following except:

a. service information may be lacking.
b. lack of knowledge about the product.
c. knowledge of how they work may be missing.
d. the warranty may have expired.

Explanation:

The expiration of a warranty has no direct relation to the difficulty of diagnosing non - OEM accessories. Lack of service info, product knowledge, and knowledge of how they work can make diagnosis hard.

Answer:

D. The warranty may have expired.