Manuel is a supervisor at a quick$-$service restaurant where employees exhibit excessive tardiness. If workers are tardy three times in one month, they receive a disciplinary written warning. Manuel gives the same warning to every employee who is late three times in one month, regardless of whether the employee is in a protected group category. This example demonstrates that Manuel is using $q,$

a$.$ affirmative action while supervising employees

b$.$ discrimination in the supervision of the employees

c$.$ the OUCH test for supervision

d$.$ an employee morale survey for supervision