The 1937 Revision of the Stanford-Binet Intelligence Scale Included Two

The 1937 revision of the Stanford-Binet Intelligence Scale included two equivalent forms labeled Form L and Form M,named as such because:

A) these were the next two sequential letters in the alphabet that had not been used to name forms of the test.
B) because Lewis Terman's full name was Lewis Madison Terman and his close friends called him "LM."
C) these were the initials of Lewis (L) and his associate in the revision, Maude (M) .
D) Terman snacked incessantly on little multicolored, candy-coated chocolates, which in the 1930s were called "L&Ms."