If the Insured's Circumstances Change During the Term of an Insurance

If the insured's circumstances change during the term of an insurance contract:

A) they have no obligation to notify the insurer unless the risk under the insurance contract is dramatically changed.
B) they must tell the insurer if the change minimises the insurance risk.
C) they must tell the insurer if the change increases the insurance risk.
D) they must tell the insurer on request even if the change is unlikely to affect the risk.