Ed Goes Out to Eat with His Friend Ralph

Ed goes out to eat with his friend Ralph.During dinner Ed receives a telephone call that his dog has escaped from his fenced backyard.He tells Ralph that he needs to leave in order to tend to the dog.Ralph tells him to go ahead and he will finish his dinner and pay their check."You can settle up with me tomorrow," Ralph tells Ed.Ed departs.Ralph finishes his dinner and pays for his meal but not for Ed's.When the waitress appears with Ed's check,she learns he has left the restaurant.Since Ed is a regular customer,the waitress knows his identity.A theft of service complaint about Ed is filed with the police.Regarding this situation:

A) Ed has committed theft of service because he obtained food and failed to pay for it.
B) Ed can successfully assert the defense of necessity because he received an emergency phone call that caused him to depart without paying.
C) Ed can successfully assert the defense of mistake of fact because he thought Ralph was paying his check and he lacked the intent to commit theft of service.
D) Ed has can successfully assert the defense of duress because the emergency forced him to depart suddenly.