Which Statement Regarding Protein Secondary Structures Is Correct?
A) $\beta$ -Strands Allow

Which statement regarding protein secondary structures is correct?

A) " $\beta$ -strands allow $\alpha$ -helices to interact with one another."
B) "Protein $\alpha$ -helices alternate with $\beta$ -strands in stabilizing protein structure."
C) "Protein $\alpha$ -helices are left handed, whereas $\beta$ -sheets are right handed in arrangement."
D) "Protein $\alpha$ -helices and $\beta$ -strands differ in that $\alpha$ -helices are stabilized by intrahelical hydrogen bonds, whereas $\beta$ -strands are stabilized by hydrogen bonds across adjacent strands."