Consider the following statements about haemoglobin:
1. It carries oxygen in the blood.
2. It is an iron-containing compound.
3. It provides immunity against certain diseases.
4. It imparts red colour to the blood.
The correct statements out of these are:
1
1, 2 and 3
2
1, 3 and 4
3
2, 3 and 4
4
1, 2 and 4