The New Terms of a Collective-Bargaining Agreement Eliminated the Employer's

The new terms of a collective-bargaining agreement eliminated the employer's obligation to provide health benefits to retired employees, except for workers who were at least fifty years old. Employees between forty and fifty years of age alleged that the agreement violated the ADEA because it discriminated against them with respect to compensation, terms, conditions, or privileges of employment, because of their age.​

A) This is an example of reverse discrimination under the ADEA and is illegal.
B) This is an example of disparate impact discrimination under the ADEA and is illegal.
C) This is an example of disparate treatment discrimination under the ADEA and is illegal.
D) All of the above.
E) None of the above. The ADEA does not prohibit discrimination against younger workers within the protected class because the enemy of 40 is 30, not 50.