X killed Y in 1920. The crime of Murder during that time was Death by Hanging. In 1932, the Penal Code was revised. The penalty for murder this time is Reclusion Perpetua. X was convicted of Murder in 1940.
What is the penalty of X?
A. X must be hanged because there is no ex post facto law!
B. Reclusion Perpetua, as he was convicted in 1940.
C. Death, since the killing was done in 1920 and that was the penalty during that time.
D. Reclusion Perpetua for the law always have prospective effect when beneficial.
E. Reclusion Perpetua, because it is beneficial.