After Their Review of Available Evidence, the National Research Council

After their review of available evidence, the National Research Council determined that research to date

A) clearly shows that the death penalty has a deterrent effect on homicide rates.
B) suggests that capital punishment deters many people considering first degree murder but only a few of those considering second degree murder and manslaughter.
C) indicates that the death penalty effectively deters women, but cannot be said to deter men from committing first degree murder.
D) cannot conclusively determine whether capital punishment decreases, increases, or has no effect on homicide rates.