The Phi ? and Psi ? angles of one alpha carbon located in the center of an alpha helix in myoglobin are -60o and -45o, respectively. Which of the following statements is CORRECT?
a. The alpha carbon described above might belong to a proline residue
b. The alpha carbon described above is expected to have very similar or identical Phi and Psi as its neighboring alpha carbons
c. The alpha carbon described above can have any set of Phi and Psi as long it is within the permissible areas of the Ramachandran plot
d. It is quite possible that the R group of this alpha carbon is pointing to the inside of the helix