Milk is converted into curd by . . . . . . .

Which of the following is responsible for the conversion of milk into curd?

$A$: After $24 \; \text{hours}$, toddy becomes unpalatable.
$R$: Toddy left for a few hours undergoes fermentation.

$A$: Cheese is one of the oldest food items in which microbes are used.
$R$: Different varieties of cheese are known by their characteristic texture,flavour,and taste.

$A$: Curd is more nutritious than milk.
$R$: $LAB$ present in curd checks the growth of disease-causing microbes.

Which process performed by microbes is used to produce the traditional drink 'Toddy'?