“I don’t believe in goblins and ghosts,” said Carlos. “I think there has to be a ____________ explanation for the strange noises that come from that old house every night.” A. ACCESSIBLE B. AWEFUL C. RATIONAL D. COMPATIBLE
The answer is C. rational because the opposite of "goblins and ghosts" which Carlos doesn't believe in (meaning he considers that possibility to be irrational) is rational.