Why should curd and sour substances not be kept in brass and copper vessels?

Why should curd and sour substance not be kept in brass and copper vessels?

Why do curd and sour substances not be kept in copper vessels ?

Assertion (A) : Pickles and sour substances are not stored in brass and copper vessels. Reason: Acids reacts with metals. A) 'A' and 'R' are correct. R is a correct reason for A. B) 'A' and 'R' are correct. R is not a correct reason for A. C) 'A' is correct, but 'R' is wrong. D) 'A' is wrong, but 'R' is correct.