This answer is
not correct. The absorption between 3500 cm-1 and 2500 cm-1
is the key to this problem since all the possible compounds contain a benzene
ring. The amine nitrogen-hydrogen stretching absorptions show two bands that occur
at 3500 cm-1 and 3400 cm-1 and these bands are not nearly
as broad and as strong as the absorption in this spectrum. You are on the right track, think about where the other
compounds absorb and try again.