You wake up and observe a cup of water spilled on the floor.

Here are four explanations that fit the evidence. Which one is most likely because it requires the fewest assumptions and new ideas?

Clumsy aliens came into your room for a look around and knocked the cup over, then floated out through the locked window without a trace. Your neighbor still has a set of your house keys from cat-sitting last year. They must secretly be a sleepwalker and have used the keys to come in. Because they were sleepwalking, they ran into the table and knocked the cup over. Your cat wandered into the room, jumped on the table and then slowly pushed the cup off the edge. Reality is an illusion because we are all part of an elaborate computer simulation. The cup is just part of the program. It doesn’t even exist.