Answer:
With respect to the employment-at-will doctrine, this is "An exception based on public policy"
Explanation:
Under the public-policy exception to employment at will, an employee is wrongfully discharged when the termination violates an explicit, well-established public policy of the state. For example, in most states, an employer can't terminate an employee for filing a workers' compensation claim after being injured on the job, or for refusing to engage in illegal activity at the request of an employer.
Public policy may be found in a state constitution, statute, administrative rule, or other state policy. The public-policy exception is the most commonly accepted exception, recognized in the vast majority of states.