Answer:
He's most likely to be B, a phlebotomy technician.
Step-by-step explanation:
A phlebotomist is someone who draws blood and even administers IV fluids to patients. You'll often see them work with needles and tubes. They draw blood and send it away for testing for certain illnesses.
It's possible that emergency medical technicians are also able to perform these tasks, but phlebotomists are more specialised.
Dental assistants work with teeth.
Pharmacy technicians work behind the counters of pharmacies, where they administer drugs and medications based on doctors' prescriptions.