To solve this question, the user needs to be familiar with the definitions of the given options and their relevance to matchboxes.
The correct answer is:
A. Cumyxaphilist
Option A is correct. A person who collects matchboxes is known as a cumyxaphilist. This term is derived from the Greek words "cumyxa," meaning a small box or case, and "philos," meaning love or affection. Hence, a cumyxaphilist is someone who loves to collect small boxes, such as matchboxes.
Option B is incorrect. Pocilliovist refers to a collector of beer mats or coasters.
Option C is incorrect. Iconophilist is someone who collects religious images or icons.
Option D is incorrect. Fusilatelist is someone who collects ammunition or firearms cartridges.
Therefore, the answer is A. Cumyxaphilist.