Study the following statements regarding lactic acid bacteria `(LAB)` which are used to convert milk into curd.
(i) They produce acids that coagulate and partially digest the milk proteins.
(ii) A small amount of curd added to the fresh milk as an inoculum contains millions of `LAB`, which at suitable temperature, multiply and convert milk into curd.
(iii) Conversion of milk into curd improves its nutritional quality by increasing vitamin `B_(12)`.
(v) LAB may result in acidity in the stomach of human beings.
Which of the given statements are correct ?