Which of the following elements are present in all proteins?
1. Carbon
2. Hydrogen
3. Oxygen
4. Nitrogen
Select the correct answer from the codes given below.

A

2 and 3

B

1, 2 and 3

C

1, 3 and 4

D

1, 2, 3 and 4

Proteins are found in all living organisms andare composed of molecules called amino acids. Each amino acid contains four elements they are hydrogen, oxygen, nitrogen and carbon and in certain cases may also contain sulfur.