Under what condition must an appliance license be reactivated?

A. Licenses only have to be reactivated for RMAs no other situations.

B. Licenses generally have to be reactivated during system software upgrades.

C. Licenses only have to be reactivated when new features are added (IPv6, Routing Modules, etc) no other situations.

D. Never. Licenses are permanent for the platform regardless the version of software installed.