In the following sentence, four words or phrases have been printed in bold. One bold part in the sentence is not acceptable in Standard English. Pick up that part and mark its number. If there are no errors in the bold parts, mark (5) i.e. No error as the answer.

Unlike drugs admnistered/(A) to the sick, vaccines have a higher/(B) bar of proving themselves safe/(C) as they are given to the healthy/(D).