A Sequence of Amino Acids in a Certain Protein Is $\beta$

Multiple Choice

A sequence of amino acids in a certain protein is found to be -Ser-Gly-Pro-Gly-. The sequence is most probably part of a(n) :

A) antiparallel $\beta$ sheet.
B) parallel $\beta$ sheet.
C) $\alpha$ helix.
D) $\alpha$ sheet.
E) $\beta$ turn.