God I read this so long ago but assuming Bob is the guy accused of beating the white guy's wife, I think the book lets the reader know that he's left handed through Atticus's demonstration when Atticus threw something at Ewell and he caught it with his left hand. Atticus then asks why he didn't catch it with his right and then Ewell says he hurt it when he was younger.
The answer is B many types of media and propaganda use
