Michael Morgan Injured His Back at Work Which Resulted in a Permanent

Michael Morgan injured his back at work which resulted in a permanent partial disability. Specifically, Michael was unable to stand or stand for long periods of time. He desired to return to work, however, he was not able to perform the duties of his old job. Michael waived the medical restrictions and returned to work anyway. He compensated for the disability by using sick days and vacation days which amounted to at least 1 to 2 days per week. After 3 months of working this schedule, he was terminated. According to the court in Pickens v. Soo Line Railroad Co.,

A) Michael has a claim for discriminatory discharge under the ADA because he could perform the "essential functions" of the job when he is able to work.
B) Michael has a claim for discriminatory discharge under the ADA because he is "otherwise qualified" for the job.
C) Michael does not have a claim for discriminatory discharge because his waiver of medical restrictions for employment eliminated his disability for purposes of the ADA.
D) Michael does not have a claim for discriminatory discharge because he cannot perform the "essential functions" of the job because regular attendance is a necessary element of the job.