Which of the Following Is True Regarding $\beta$ -Sheet Structures?
A)hydrogen Bonds in an Parallel Sheet Are Non-Linear

Which of the following is true regarding $\beta$ -sheet structures?

A) hydrogen bonds in an parallel sheet are non-linear
B) hydrogen bonds in an antiparallel sheet are non-linear
C) the rise per residue is greater for a parallel sheet than for an antiparallel sheet
D) $\beta$ -sheets are an n=3 helix with each residue rotated 120 ^$\circ$ with respect to its neighbors
E) none of the above