The solubility of NaNO$_3$ in water is 73 g/100 mL at 0°C and 180 g/100 mL at 100°C. From this we can conclude that:
A) NaNO$_3$ is insoluble in water
B) The enthalpy of solution, $\Delta H_{soln}$, is negative
C) The enthalpy of solution, $\Delta H_{soln}$, is positive
D) NaNO$_3$ is more soluble at lower pressure
E) NaNO$_3$ is a non electrolyte