What does the term "quasi-equivalent" mean with respect to the proteins in an icosahedral capsid?

A) If the identical protein is used, it has both 5-fold and 6-fold interactions with the other proteins in the capsid.
B) There are different proteins in the capsid with similiar shapes.
C) They all use the "jelly-roll" protein structure.
D) There can be more than one type of glycoprotein in the envelope.
E) All of the proteins interact in a 5-fold arrangement.