Which of the following pairs of solutions is isotonic?

At $300 \ K$,$6 \ g$ of urea was dissolved in $500 \ mL$ of water. What is the osmotic pressure (in $atm$) of the resultant solution? $(R=0.082 \ L \ atm \ K^{-1} \ mol^{-1})$ $(C=12; N=14; O=16; H=1)$

At a constant temperature,the osmotic pressures of a $1.5 \ M \ NH_4NO_3$ aqueous solution and an $x \ M \ Al_2(SO_4)_3$ aqueous solution are approximately equal. Find the value of $x$. (Assume $100 \%$ dissociation of the solute in the solution.)

The osmotic pressure of equimolar solutions of $BaCl_2$,$NaCl$,and glucose follows the order:

The osmotic pressure exerted by a solution prepared by dissolving $2.0 \ g$ of protein of molar mass $60 \ kg \ mol^{-1}$ in $200 \ mL$ of water at $27^{\circ} C$ is $.....Pa$. [integer value]
(use $R = 0.083 \ L \ bar \ mol^{-1} \ K^{-1}$)

$200 \, cm^3$ 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 $2.57 \times 10^{-3} \, bar$. Calculate the molar mass of the protein.