Answer:
c. The suspect was in the room where the victim was found because of the matching carpet fibers.
Explanation:
Locard's exchange principle states that the perpetrator of a crime will leave with something from a crime scene or bring something into the crime scene. These will be used as evidence to get the perpetrator.
From this question, option A is incorrect because the bullets on the victim did not match with the pistol of the suspect, hence Locards principle does not apply.
Option B is also incorrect because the car could have been driven there by someone else or could have just been parked there.
Option D is also incorrect because though the presence of similar fibre carpets on the victims appartment and on the suspect indicate the suspect was in the apartment, does not necessarily mean he commited the crime, he may have been there days earlier or he may have been there that day for other reasons.
Option C fits better.