Why Do Astronomers Believe the Binary Companions of the White

Why do astronomers believe the binary companions of the white dwarfs that produce Type Ia supernovae are MOST probably main-sequence stars?

A) Only main-sequence stars have lifetimes that would allow them to fill their Roche lobes at the same time their companion (formed at the same time) is a white dwarf.
B) We detect white dwarf binaries mostly by the astrometric method of looking for a wobble in the primary star's motion. Only a main-sequence star would be massive enough for this wobble to be detected.
C) A smaller star would not be able to fill its Roche lobes, and a larger star would swallow the white dwarf before it could produce a supernova.
D) The supernova explosion will cause the atmosphere of the binary companion to glow. We do not detect enough afterglow to suggest a giant or supergiant as companion.