Which Observation Would NOT Be an Indication of a Binary

Multiple Choice

Which observation would NOT be an indication of a binary star system?

A) The "star" appears to move in a straight line against a background field of stars.
B) A "star" appears to become periodically dimmer and then brighter for a few hours at a time.
C) A "star" image periodically separates into two distinct images and then blends again.
D) The "star" appears to wiggle in its path across Earth's sky against the background stars.