# The secondary structure of protein refers to

$\begin {array} {1 1} (A)\;\text{sequence of$ \alpha$amino acids }\\ (B)\;\text{fixed configuration of the polypeptide backbone} \\ (C)\;\text{$ \alpha$helical backbone}\\ (D)\;\text{hydrophobic instructions} \end {array}$

The secondary structure of proteins refers to fixed configuration of polypeptide chain
Ans : (B)