My argument is this: From the context supplied (which is none) there is absolutely no way of knowing whether the word "(ku)pasua" or "chozi" is intended. So either answer should be correct. I think the Swahili infinitive should be accepted here too, since (again from lack of context) we don't know if this is a command (Pasua!) or just a vocabulary exercise (kupasua)
It's a verb though. You can't have a pasua in your pants ... you can kupasua your pants and then you have a ...
mpasuo (pl mipasuo)
mpasuka (pl mipasuka)
mpasuko (pl mipasuko)
raruo (pl mararuo)
ufa (pl nyufa)
... in them.
If this is the verb "tear," could "rarua" also be used? (My reference shows "pasua" means to burst or split.)