Explanation:

- Haemoglobin and myoglobin are essential proteins in the body. Haemoglobin is found in red blood cells and is responsible for carrying oxygen from the lungs to tissues. Myoglobin is found in muscle tissue and stores oxygen for when it is needed.

- Iron is a crucial component of haemoglobin and myoglobin. It allows these proteins to bind and release oxygen effectively.

- Option 1: Iron is correct. Both haemoglobin and myoglobin require iron for their formation.

- Vitamin B12 is essential for red blood cell formation and neurological function but not directly involved in forming haemoglobin or myoglobin.

- Calcium is important for bone health, but it does not play a direct role in the formation of haemoglobin or myoglobin.

- Vitamin A is vital for vision and immune function but not directly related to haemoglobin and myoglobin formation.