Obsessed with True Crime discussion

In the Spike Lee movie BLACKKKLANSMAN, Ron Stallworth gave his real name when he first contacted the KKK because he just wasn't thinking ahead. What was the reason Stallworth gave in his memoir?

A) He only sent for printed materials and never expected the phone call he got later
B) He was still waiting for his superiors to issue him an alias and didn't want to wait
C) There were so many Ron and R. Stallworths in the phone book he didn't think it would matter
D) Some other reason (explain)

A) He only sent for printed materials and never expected the phone call he got later

DING DING DING! It would have been equally correct to answer D) and say he never expected the literature request to result in an investigation, because he believed someone had probably posted the ad as a gag.