In humans, calcium plays a role in

(A) Bone formation

(B) Blood clotting

(C) Muscle function

(D) Blood formation

Choose the correct answer from the options given below:

Option 1 -> Includes blood formation (D), which is incorrect as calcium doesn't directly participate in hematopoiesis.

Option 2 -> Correctly identifies bone formation, blood clotting, and muscle function as roles of calcium, excluding blood formation.

Option 3 -> Incorrectly includes all four options including blood formation.

Option 4 -> Excludes bone formation (A) which is incorrect, and includes blood formation (D) which is also incorrect.

Hence, Option 2: (A), (B) and (C) only -> Calcium is essential for bone mineralization (99% of body's calcium is in bones), serves as a crucial cofactor in the blood clotting cascade, and triggers muscle contraction by binding to troponin. However, calcium does not play a direct role in blood formation (hematopoiesis), which is primarily regulated by erythropoietin, iron, and vitamins B12 and folate -> correct