A warning banner and a stated intention to prosecute unauthorised access are deployed. Which control type does IR 8286 classify these as?

Answer: B. Deterrent

IR 8286 defines a deterrent control as reducing the likelihood of a threat event by dissuading a threat actor, and uses warning banners and the threat of prosecution as its example.

Source: NIST IR 8286 (NIST) — Sec. 3.5.1 Applying Security Controls