This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Dental
Which among the following is computer controlled injection system: 
Select and explain. 
A. WAND., B. TENS., C. Denti patch., D. Jet injections.
A: WAND.
Answer: A: WAND. 
Explanation: It is a computer controlled injection system in which dosage is controlled by computer.