Suppose Earth Existed in a Solar System Containing Two Stars

Multiple Choice

Suppose Earth existed in a solar system containing two stars, relatively close together. What major change would result from such an arrangement compared to the situation at present?

A) No substantial change would result.
B) There are no stable orbits for such a system, so Earth would be doomed to fall into one of the stars.
C) We would be in an orbit in which one star or the other would always be in the sky, and, without a night, our biosphere would have developed differently.
D) We would have to be in a highly elliptical orbit giving us extremes in temperature.