Westworld 1973 Problem #1

Peter flees from the unstoppable Gunslinger android into Delos' main Robot Repair Bay. Recalling the Delos Technician's prior warning, the Gunslinger's visual optics can be damaged from acids. If the Repair Bay stocks vials of:

1) Acetic Acid $(\ce{CH_{3}COOH})$ ,
2) Sulfuric Acid $\ce{(H_{2}SO_{4}})$ ,
3) Hydrochloric Acid $(\ce{HCl})$ ,
4) Nitric Acid $(\ce{HNO_{3}})$

and each vial contains $0.05$ M of acid, which would inflict the least damage (by pH level) to the unsuspecting Gunslinger?

NOTE: This is the first of a series of problems I'll be creating in homage to Michael Crichton's 1973 sci-fi classic 'Westworld'. I have always held this film as an early afflatus to my love of Electrical Engineering & Advanced Mathematics!!!

Try out Westworld 1973 Problem #2!!!