Thread safety object - static or not?

Question

I was recently in an interview and the tech guy asked me about how to make an application thread-safe.

Well, after explaining the lock() correctly, he s

Answer 1

He claimed the reason is that static is run at runtime instead of compilation and would make that object slower for threads to lock than if it was non static.

This doesn't really make any sense - I think either the interviewer did not know what he was talking about, or maybe you misunderstood his point.