I have been asked a question on an inspection quiz and it asks :"which of the following is a legal and commonly used trap?". A) Bell Trap. B) S trap. C) Drum Trap. D) P trap.

I think they're all commonly used traps. Am I missing something or are a couple of them illegal nowadays? Thanks AJ

The only legal trap is a p-trap... unless you are in Maine, and then a drum trap can be used within 10 feet of the waste stack (no vent required here). Especially the way the quiz question was phrased... which of the following is a legal trap... suggests looking for only one answer... but I could be wrong. Hope this helped!

"I think they're all commonly used traps." Nope not in these united states. Last to go was the S trap leaving P as the only one allowed by IBC. What kind of inspection test are you taking, home inspection qualification?