When approved by the commission, a common carrier may give free or reduced rate transportation between points within this state to:
(a)
Its officers, agents, employees, and members of their families.
(b)
Indigent, destitute, and homeless persons, and to such persons when transported by charitable societies or hospitals, and the necessary agents employed in such transportation.
(c)
Persons injured in accidents or wrecks, and physicians and nurses attending such persons.