The Method Used in the Urey-Miller Experiment Was To

The method used in the Urey-Miller experiment was to:

A) pass an electric arc through a mixture of hydrogen, ammonia, methane, and water and then look for organic compounds.
B) send radio signals using a pulsed code toward nearby Sun-like stars that may have planets.
C) attach a metal plaque to the Voyager spacecraft to tell extraterrestrial beings about us, if they ever find the spacecraft.
D) monitor tens of millions of frequencies at once in an effort to detect extraterrestrial radio communications.