Explanation

(d)
Osmotic pressure is a colligative property i.e., depends only upon the number of particles or ions in solution. More the number of ions in solution, more will be the osmotic pressure of solution
(i) 0.1 M urea and 0.1 M glucose will have same number of molecules in solution as they do not ionise.
(ii)$\ KCl\ {\rightarrow K}^{+} + Cl^{-}(2\ ions)$
$CaCl_{2} \rightarrow Ca^{2 +} + \ 2Cl^{-}\ (3\ ions\ )$
$\therefore$ $CaCl_{2}$ produces maximum number of ions.
$\therefore$ It will have highest osmotic pressure.