Given a set of five words, generate the word from the set that does not belong (i.e. is the least relevant) with the other words. Words are separated by commas.

Q: duplex, studio, cabin, horizontal, flat

A: horizontal
****
Q: cool, relaxed, mild, unflappalbe, assured

A: mild
****
Q: concrete pourer, davit, neck, tackle, crane

A:
neck
****