Ferroequinology

I don't know if the person who set this question ever googled the word in question. If they did (and their version of Google works the same as mine) the first result they saw would have been the entry in Wiktionary. This describes the word as "humorous, nonstandard".

In other words, ferroequinology is not actually the study of anything. It is, quite literally, a word that was made up as a joke – a pun on the idea that a railway locomotive is an 'iron horse'. I hardly need add that IMHO, this question should never have been asked in a quiz.

I might add, however, that my only thought, when I did hear the question, was of horseshoes.