474. Legend has it that when the Mohawk Joseph Brant was presented to George III in 1776, he proudly refused to kiss the King's hand, inasmuch as he regarded himself an ally, not a subject.
(A) as he regarded himself an ally, not
(B) that he regarded himself to be an ally rather than
(C) as he considered himself an ally, not
(D) that he considered himself to be ally instead of
(E) as he considered himself as an ally rather than

Why C is a better option than A. Is 'regarded himself' a wrong usage?