Final answer:
The claim that capital punishment can deter crime is best supported by the fact that it prevents recidivism. While broader deterrence is debated, the death penalty ensures individuals cannot reoffend.
Step-by-step explanation:
The statement that best supports the claim that capital punishment can be an effective deterrent is 'd) Capital punishment prevents recidivism.' This is because once the death penalty is applied, the convicted individual no longer has the opportunity to commit further crimes, thus ultimately preventing the possibility of reoffending. While it is a debate whether the death penalty effectively deters prospective criminals, it is certain that it eliminates the specific individual's capacity to commit further offenses.
Even though some research indicates that capital punishment may not effectively deter offenders from committing homicide on a broader scale, the death penalty advocates argue that the lack of possibility for reoffending contributes to its overall effectiveness as a deterrent. Importantly, the Supreme Court has ruled that the death penalty itself is not inherently cruel and unusual punishment, allowing for capital punishment under specific conditions and acknowledging its potential deterrent effect.