"Punishments Are More Effective in the Longer Term

"Punishments are more effective in the longer term." This is because:

A) Over time the threat of punishment is often enough to induce cooperation without a lot of actual punishment having to be carried out.
B) Typically, the frequency and magnitude of punishment increases over time.
C) In the long run, one can combine both monetary and non-monetary sanctions.
D) In the long run, people can engage in endogenous sorting and choose who they wish to play with.