Which vitamin content is increased by Lactic Acid Bacteria $(LAB)$ in milk?

Dough kept overnight in warm weather becomes soft and spongy because of

$A$ released by $LAB$ during growth coagulate and partially digest $B$. Here $A$ and $B$ refer to:

Choose the correct sentences.
$(i)$ Dosa and Idli are fermented by bacteria, not yeast.
$(ii)$ $Saccharomyces \text{ } cerevisiae$ is a yeast.
$(iii)$ $LAB$ (Lactic Acid Bacteria) increase the nutritional quality of milk by increasing vitamin $B_{12}$.
$(iv)$ Whisky and brandy are fermented beverages produced by distillation.

Milk is converted into curd $(yoghurt)$ by the biological activity of:

Which of the following is used in the production of bread?