Which Type of Information Below Helped Determine the Subunit Composition

Which type of information below helped determine the subunit composition and stoichiometry of nAChRs?

A) Position of ligand binding sites at α-γ and α-δ interfaces
B) Affinity for α-bungarotoxin
C) Electron imaging and other physical techniques
D) Molecular weight of the purified Torpedo nAChR and its constituent subunits
E) More diameter and relative selectivity of large cations