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
Only mydriatic action is by- 
Select and explain. 
A. Tropicamide, B. Homatropine, C. Phenylephrine, D. Cyclopentolate
C: Phenylephrine
Answer: C: Phenylephrine 
Explanation: Ans. is 'c' i.e., Phenylepherine Phenylepherine is used as a mydriatic when cycloplegia is not required. It reduces the i.o.t. by constricting ciliary body blood vessels. It is also used as a nasal decongesent. About other options o Tropicamide, homatropine and cyclopentolate are mydriatic as well as cycloplegic.