Why is boiling point of water increased on addition of sodium chloride into it ?

Question

$\begin{array}{1 1} \text{(a) Because a solution has a lower boiling point than a pure solvent.}\\ \text{(b) Because a solute has a higher boiling point than a pure solvent.} \\ \text{(c) Because a solution has a higher boiling point than a pure solvent.} \\(d)\;\text{Because a solution has a equal boiling point as a pure solvent.} \end{array}$