If an Extraterrestrial Being Were to Send a Signal to Earth

Multiple Choice

If an extraterrestrial being were to send a signal to Earth immediately to confirm the sighting in 2018 of a nuclear explosion on Earth in July 1945, and we were ready to receive such a message, when would we expect it? (Note to instructors: This question is linked to the previous question.)

A) 2032 C.E.
B) 2127 C.E.
C) 2016 C.E.
D) 2077 C.E.