[A] : Peptide bonds are present in primary , secondary & tertiary structures of proteins .
[R] : All structures of protein contain amino acids .

Options

A. (a) If both A and R are true and R is the correct explanation of A
B. (b) If both A and R are true but R does not explain A
C. (c) if A is true and R is false
D. (d) If both A and R are false