Which One of the Following Explains the Effect of a Co-Insurance

Which one of the following explains the effect of a co-insurance clause?

A) A co-insurance clause provides for the insurance company arranging their own insurance on a large policy.
B) A co-insurance clause provides for several different properties being insured under the same policy.
C) A co-insurance clause provides for more than one person paying the premium.
D) A co-insurance clause provides for the insured to assume part of the responsibility for any loss.
E) A co-insurance clause provides for the insurance claim to be split between two or more beneficiaries.