Frank Drake Began His SETI Investigations by Listening for Signals

Multiple Choice

Frank Drake began his SETI investigations by listening for signals from two particular stars: Ʈ Ceti and ɛ Eridani.Why these two?Ʈ

A) These are among the half dozen closest stars to Earth.
B) These stars are similar to the Sun.
C) It was thought that previous signals had been detected from these sources.
D) These stars are both very old and thus would have had time to evolve an advanced civilization.