The correct answer is C) They were executed by the electric chair.
The punishment for the Rosenbergs, who were convicted of providing bomb secrets to the Russians was "They were executed by the electric chair."
Julius and Ether Rosenberg were a couple that was accused in 1951 of espionage on behalf of Russia. They were found guilty of providing the Soviet Union with classified information about nuclear weapons. The United States government considered this unacceptable in the times of the Cold War years when the US was the only country capable of developing nuclear bombs. The couple was executed in the Sing prison, in Ossining, New York, in 1953.