Amines are organic compounds that contain a derivative of ammonia (NH4). In this case we have an amine that has two alkyl groups attached, the ethyl group and the methyl group.
The ethyl group is a group with two carbons, and the methyl group contains one carbon. In both options we see the ethyl group and the methyl group linked to the nitrogen to form the ethylmethylamine.
Therefore, the answer will be: C. Both