Which of the following arguments is an ad hominem?

A、Honest Abe told me that it will rain today, therefore, it will probably rain today.
B、Lying Larry told me that it will rain today, therefore, it probably will not rain today.
C、Vague Vinny told me that it will rain today, but there’s no substantial difference between raining and drizzling, therefore Vinny will end up having been right even if it just drizzles.
D、Raspy Ralph told me that it will snow, and therefore, he must have heard the weather report.
E、Screaming Sam told me that it will snow today, but he's wrong.