Answer: Option (3) is the correct answer.
Explanation:
It is known that general chemical formula of an amine is [tex]R-NH_{2}[/tex]. Where R is any alkyl group and [tex]-NH_{2}[/tex] represents the amine group.
On the other hand, an aldehyde group is represented by CHO and general formula R-CHO. So, there is no nitrogen atom present in an aldehyde group.
An alcohol group is represented by -OH and general formula R-OH. There is also no nitrogen atom present in an alcohol.
An ether group is represented by -O and general formula R-O-R' where R and R' might be same or different alkyl groups. Hence, there is also no nitrogen atom present in an ether.
Thus, we can conclude that out of the given options amine is the class of organic compounds which contains nitrogen.