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: Pharmacology
Which of the following is the shortest acting mydriatic among the following: 
Select and explain. 
A. Atropine., B. Homatropine., C. Cyclopentolate., D. Tropicamide.
D: Tropicamide.
Answer: D: Tropicamide. 
Explanation: None