A patient repeatedly complains that neighbors are plotting against him, trying to harm him without evidence. This belief is best described as:

Correct option is B

Delusion of persecution = false, fixed belief of being conspired against or harmed by others, a common type in schizophrenia.
Explanation of options: (a) ✘ Delusion of reference = believing TV/radio talks about him. (b) ✔ Correct; persecution = belief of being harmed or plotted against. (c) ✘ Grandeur = false belief of having special power/importance. (d) ✘ Thought broadcasting = belief that others can hear one’s thoughts.