An established patient was seen in his primary physician's office. The patient fell at home and came to the physician's office for examination. Due to a possible concussion, the patient was sent to the hospital to be admitted as an observation patient. A detailed history and examination were performed, and the medical decision was of low complexity. The patient stayed overnight and was discharged the next afternoon. Report code(s) _____.

a. 99214, 99234
b. 99214, 99218, 99217
c. 99218
d. 99218, 99217

d