Final answer:
Keith, with a doctorate in emergency medicine, would be most appropriately placed as an intern at a small emergency department, where he can utilize and further develop his skills. Hence, option (a) is correct.
Step-by-step explanation:
Keith has just graduated with a doctorate in emergency medicine. Considering his advanced education, Keith would be best suited for a role that requires a high level of expertise and decision-making skills in a clinical setting. The most appropriate position for someone with Keith's qualifications would be an intern at a small emergency department.
This role would allow him to apply his extensive knowledge and expertise in a hands-on environment where he can further develop his practical skills under supervision. While he is overqualified to be an emergency room nurse or orderly, he would not yet have the experience required to be the head of an emergency department in a large hospital.