Which coverage under a dwelling policy would not apply to an insured using the property for commercial activities?

Coverage D - Fair Rental Value is specifically designed to provide compensation for the loss of rental income if a rented property becomes uninhabitable due to a covered peril. This coverage is generally applicable to residential situations where the property is rented out as a dwelling. When the insured uses the property for commercial activities, it shifts the context from residential rental to a commercial enterprise, which is not within the parameters of this coverage.

The other types of coverage, such as Coverage A (Dwelling), Coverage B (Other Structures), and Coverage C (Personal Property), may potentially provide some degree of protection depending on the policy specifics and circumstances. However, Coverage D clearly pertains to residential rental operations, making it inapplicable when the property is being utilized for commercial purposes. Thus, it is the least relevant in scenarios involving business activities on the premises.