Which of These Major Perturbations Can Occur to a Close

Multiple Choice

Which of these major perturbations can occur to a close binary system and radically alter the evolution and behavior of the two individual stars?

A) gravitational disturbance of one star's motion by its companion to force it to move in an orbit
B) transfer of matter from one star to its companion
C) heating of the localized areas of the atmosphere of one star by its companion
D) eclipsing of the light from one star by the other when viewed from Earth