How to fill in the control type of heavily polluted weather

A, b or leading enterprises. Heavy pollution weather control types are divided into key industry security enterprises (A-level, B-level or leading enterprises) and non-key industry security enterprises (people's livelihood exemption). Regulation means that the government takes measures to manage and control the area because something happens in a certain place that affects people's lives and safety, and it is strictly forbidden to move people before the danger is lifted.