What Is It That Distinguishes an Insurance Contract from an Ordinary

What is it that distinguishes an insurance contract from an ordinary business contract?

A) There is uncertainty that could result in either a gain or a loss.
B) Both parties believe that the contractual price and the value of the contractual goods are equivalent.
C) The insured will receive a sum of money on the occurrence of an event which must occur at some time, although the time of the occurrence is uncertain.
D) One party knows that they are paying a price far less than the value provided by the other party and that the other party will only have to perform if certain conditions are met.