Arrange the following steps of curd formation from milk.(A) Coagulati…

The correct answer is Option (2) → (D), (B), (C), (A)

(D) A small amount of curd is added as an inoculum to fresh milk — first. This starter brings millions of lactic acid bacteria into the milk.

(B) Growth of starter culture — second. At a suitable warm temperature the starter bacteria multiply.

(C) Growth of lactic acid bacteria (LAB) in milk — third. The LAB spread through the milk and produce lactic acid as they grow.

(A) Coagulation and partial digestion of milk protein — last. The acid sets the milk proteins and partly digests them, and the milk becomes curd.

NCERT Extract:
Microbes in Household Products – “… You would be surprised to know that we use microbes or products derived from them everyday. A common example is the production of curd from milk. Micro-organisms such as Lactobacillus and others commonly called lactic acid bacteria (LAB) grow in milk and convert it to curd. During growth, the LAB produce acids that coagulate and partially digest the milk proteins. A small amount of curd added to the fresh milk as inoculum or starter contain millions of LAB, which at suitable temperatures multiply, thus converting milk to curd, which also improves its nutritional quality by increasing vitamin B₁₂.”