Consider the following solutions, A=0.1 M glucose, B=0.05 M NaCl ,...

Isotonic solutions have same molar concentration of solute particles in solution. Molar concentration of particles in solution are (a) = 0.1 M in glucose (b) $=2 \times 0.05 \mathrm{M}$ in NaCl (c) $=3 \times 0.05 \mathrm{M}$ in $\mathrm{BaCl}_2$ (d) $=4 \times 0.1 \mathrm{M}$ in $\mathrm{AlCl}_3$ Hence, 0.1 M glucose and 0.05 M NaCl solutions are isotonic.