Health Clinic Inc. has no written employment manual or oral discharge policy, avoids abusive treatment of its staw, and acts to prevent illegal and unsal activities. The clinic freely hires and fires its employees, who are similarly free to quit at any time. With respect to the employment$-$at$-$will doctine, this ib

a$.$ an exception based on contract theory.

b$.$ an exception based on a statute.

c$.$ exemplary of the doctrine

d$.$ in direct conflict with the doctrine.