Introduction:
Macro minerals, also known as major minerals, are essential nutrients that are required by the body in relatively large amounts. They play important roles in various physiological processes and are necessary for maintaining overall health. Copper, calcium, iodine, and cobalt are all examples of macro minerals. However, in this case, the correct answer is option 'B' - calcium.

Explanation:
Calcium:
- Calcium is a mineral that plays a crucial role in the development and maintenance of strong bones and teeth.
- It is also involved in muscle contraction, nerve function, blood clotting, and cell signaling.
- Calcium deficiency can lead to conditions like osteoporosis, muscle cramps, and impaired blood clotting.

Copper:
- Copper is an essential mineral that is involved in the production of red blood cells and the maintenance of a healthy immune system.
- It also plays a role in energy production, collagen synthesis, and iron metabolism.
- Copper deficiency can result in anemia, bone abnormalities, and impaired immune function.

Iodine:
- Iodine is a vital mineral that is necessary for the production of thyroid hormones, which regulate metabolism, growth, and development.
- It is particularly important during pregnancy and early childhood for proper brain development.
- Iodine deficiency can lead to goiter, hypothyroidism, and intellectual disabilities.

Cobalt:
- Cobalt is a trace mineral that is required for the synthesis of vitamin B12, which is essential for the production of red blood cells and the maintenance of nerve cells.
- It is also involved in energy production and the metabolism of fatty acids.
- Cobalt deficiency is rare in humans, but it can result in anemia and neurological problems.

Conclusion:
In conclusion, calcium is not an example of a macro mineral. It is important to understand the roles and functions of different minerals in the body to ensure a balanced and healthy diet.