The correct answer is a persecutory delusion
A persecutory delusion refers to a type of illogical and unfounded fixed and enduring belief that someone or some group is conspiring against you, tracking you, spying on you, or harassing you. For instance, you might have a persecutory delusion that the government is releasing toxins in the air in order to control the population's mind. Since Simon is certain that every time he unlocks his front door, he is actually being tricked into opening up his mind to allow aliens to spy on his thoughts, he is experiencing a persecutory delusion.