Answer:
Forty days.
Explanation:
Health insurance may be defined as the insurance that covers the partial or whole risk of the person includes the medical expenses. The health care risk are covered in the insurance policy.
M's insurance company denies the reinstatement application for her lapsed health insurance policy. In this case the company can notify the denial within the forty days. This is the rule according to the U.S. health insurance policy to notify the denial within 40 days.
Thus, the answer is 40 days.