With no explanation, chose the best option from "A" or "B". Jane discovered that someone has eaten the sandwich she left on the kitchen counter for herself, with suspects including her dog and her roommate. Jane wants to eat a sandwich.

A: Jane sees mustard surrounding the outer parts of her dog's mouth, realizes he was the culprit, and makes a replacement sandwich for herself.
B: Jane accuses her roommate of taking her food, as he has done once before, and eats a sandwich he was keeping in his fridge.
A.