This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: A.N.S., Subject name: Pharmacology
Fastest and briefest action occurs in 
Select and explain. 
A. Atropine, B. Homatropine, C. Tropicamide, D. Cyclopentolate
C: Tropicamide
Answer: C: Tropicamide 
Explanation: (Tropicamide): (118-KDT 7th edition)TROPICAMIDE - has quickest (20-40 min) and briefest (3-6 hours) action but is a relatively unreliable cycloplgic* It is satisfactory for refraction testing in adults and as a short acting mydriatic for fundoscopy* The mydriatic action can be augmented by combining with phenylephrine