Triskadeccaphobia is the fear of what?

Triskaidekaphobia is the term used to describe the irrational fear of the number 13. This phobia is rooted in various cultural beliefs and superstitions that associate the number with bad luck or misfortune. The apprehension surrounding this number is particularly notable in Western cultures, where it is often avoided in building floors, hotel rooms, and other occurrences—leading to a notable societal impact. Thus, the choice reflecting the fear of 13 is the correct answer.

The other options presented (15, 14, and 12) do not hold significant cultural associations regarding fear, making them less relevant in the context of phobias centered around numbers.