Which of the following is a colligative property?

$A$ solution of urea contains $8.6 \ g/L$ (mol. wt. $60.0$). It is isotonic with a $5\%$ solution of a non-volatile solute. The molecular weight of the solute will be:

The osmotic pressure of blood is $7.47 \, bar$ at $300 \, K$. To inject glucose to a patient intravenously,it has to be isotonic with blood. The concentration of glucose solution in $g \, L^{-1}$ is $......$ (Molar mass of glucose $= 180 \, g \, mol^{-1}$,$R = 0.083 \, L \, bar \, K^{-1} \, mol^{-1}$) (Nearest integer)

$A$ graph of osmotic pressure $(\pi)$ vs molarity $(M)$ of an aqueous solution of $NaCl$ at room temperature is given below. The slope of the line represents :-

When does the osmotic pressure of a solution increase?

Assertion $(A)$: Blood cells collapse when suspended in saline water.
Reason $(R)$: Cell membrane dissolves in saline water.