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: Ophthalmology
Method followed to decrease post-op infection in cataract surgery –a) Pre – op antibioticsb) Intra op antibioticsc) Post op subconjunctival gentamicin injectiond) Post op IV antibiotics 
Select and explain. 
A. ac, B. a, C. ad, D. ab
D: ab
Answer: D: ab 
Explanation: None