Identify the essential amino acids from the following.

(A) Threonine
(B) Serine
(C) Histidine
(D) Lysine

Choose the correct answer from the options given below:

(A), (C) and (D) only

The correct answer is Option (4) → (A), (C) and (D) only

Essential amino acids are those that the human body cannot synthesize in sufficient quantity and must be obtained from diet.

Option-wise Explanation

(A) Threonine

Essential amino acid. Needed for protein balance and immune function.

(B) Serine

Non-essential amino acid. The body can synthesize it from other metabolites (like glycine).

(C) Histidine

Essential amino acid (especially important during growth and for hemoglobin formation).

(D) Lysine

Essential amino acid. Important for growth, tissue repair, and enzyme production.