What does a typical co-insurance clause in an insurance policy require from the business owner regarding the coverage of the replacement cost or actual cost of the building?

A) Insure for at least 70% of the replacement cost.
B) Insure for at least 80% of the replacement cost.
C) Insure for at least 90% of the actual cost.
D) Insure for at least 60% of the actual cost.