Spy vs. Spy. We have captured 5 spies. Their names are A, B, C, D, and E. Here is a summary of what we know: Spy A says he knows 4 others, B 3, C 3, D 2, and E 1. If a spy is lying, he knows more people than he claims. There is no more than one liar. C is truthing.

(1) How can you tell someone is lying? Explain!

(2) Show that B must know C.

Please include detailed solutions! Thank you!!