How does a crisis differ from an emergency?

a$.$ Unlike an emergency, a crisis is not necessarily unexpected, and the organization is not necessarily disrupted while this change grows closer in time.

b$.$ Unlike an emergency, a crisis represents a disruption that is too large to be answered by any single organization.

c$.$ Unlike an emergency, a crisis is a political declaration that always requires the involvement of the government.

d$.$ Unlike an emergency, a crisis is unexpected and always signals a threat to human life and property.