Eric Was Scheduled for Trial as a Result of a Felony

Eric was scheduled for trial as a result of a felony offense. It was soon discovered that he was certain that the light fixtures throughout his city were purposely set there by aliens trying to learn how to "fit in." He was found incompetent to stand trial, but not because of his alien theory. He was found incompetent because:

A) his delusions hampered his ability to assist in his own defense because he believed that the judge and jury were aliens as well.
B) his delusions hampered his ability to understand that aliens don't exist and, even if they did, they wouldn't tamper with the trial.
C) his ability to see aliens interfered with his sense of right and wrong.
D) aliens had obviously committed the crime.