Which Statement Is Correct About the β−α−β Motif

Multiple Choice

Which statement is correct about the β−α−β motif?

A) The two β-strands are antiparellel.
B) The peptide segment connecting the β-strands usually contains no more than five amino acids.
C) The peptide segment connecting the two β-strands commonly contains proline.
D) The cross-over connection itself contains an α-helical segment.
E) none are correct.