Correct Answer is A, Discrimination.
Workplace Discrimination is when an employee is treated poorly because of the protected characteristic.
Discrimination is the unequal treatment between people. This unequal treatment on the workplace or any other place can be on the basis of different characteristics, for example, Gender, race, ethnicity, age, skin color, origin, religion, physical or mental disability, etc.
Workplace Discrimination happens when employee is treated unequal on the basis of above mentioned characteristics.