The Points in the Ramachandran Plot Are Derived by $\phi$ And $\Psi$

Multiple Choice

The points in the Ramachandran plot are derived by

A) counting the number of amino acids and placing points in allowed regions.
B) measuring the $\phi$ and $\Psi$ angles in an experimentally determined protein crystal structure.
C) placing each amino acid in regions commonly occupied by that amino acid.
D) experimentally measuring the optical rotation of polarized light.