Key features of so-called nudges include the following, except that

A) they are subtle.
B) they induce changes in behavior without bullying or coercion.
C) they involve significant monetary incentives.
D) they can be viewed by some as manipulation.

Nudges are designed to influence decisions and behavior in a predictable way without forbidding any options or significantly changing their economic incentives. The key idea is to make it easier for people to make a certain decision, but not through significant monetary incentives.