The comma in the sentence above is used incorrectly because it <span>attempts to separate a compound predicate. The comma is incorrectly used to split a compound predicate which shares the same subject. The predicate must need equal access to the subject that's why no comma is needed.</span>
Explanation:
as customer or client you may have once been to a restaurant that caries about it's client where you saw a waiter being fired because he had untidy hairstyle
Sentence C it has all the right capital letters and punctuation. But I don't think the word "have" makes sense in that sentence.