Fifty-Five Year Old Mark Has Worked with an Organization for 20

Fifty-five year old Mark has worked with an organization for 20 years and was looking forward to his impending promotion. During his annual appraisal, his supervisor stated that he had "put in enough time" and suggested he step down from his post since most executive employees retired at the age fifty five. In this instance, Mark does not need to resign since:

A) he is physically fit to work.
B) under Age Discrimination in Employment Act mandatory retirement of such executives prior to sixty-five is still prohibited.
C) retirement will violate Americans with Disabilities Act.
D) it is mandatory for his organization to hand him the promotion considering his age and level of experience.