• Discovery of Essential Amino Acids: Formulated by William C. Rose in the 1930s, who discovered the last essential amino acid, threonine (1935), and demonstrated the specific dietary requirement for 10 indispensable amino acids in animals.
• Other Concepts:
• Essential fatty acids: Burr and Burr (1929).
• Vitamins: Casimir Funk (1912).

Correct option: (4) Essential amino acids

• Statement (I) is False: In extensive free-range poultry farming, recommended stocking density is $100\text{ to }150\text{ birds per acre}$ (maximum 200–250 with pasture rotation; 200–220 fixed without rotation exhausts pasture).
• Statement (II) is True: Built-up deep litter undergoes intense aerobic and anaerobic bacterial fermentation, synthesizing significant quantities of Vitamin $B_{12}$ (cobalamin) and Riboflavin (Vitamin $B_2$), which are ingested by foraging birds.
• Conclusion: Statement (I) is false, but Statement (II) is true.

Correct option: (4) Statement (I) is false but Statement ({I) is true.