200 cm³ of an aqueous solution of a protein contains 1.26 g of the protein. The osmotic pressure of such a solution at 300 K is found to be 2.57 × 10^-3 bar.  The molar mass of the protein is-

1. 61,022 g mol^-1
2. 65,042 g mol^-1
3. 68,012 g mol^-1
4. 57,012 g mol^-1