ANS:D - both (b) and (c).

The boiling point elevation of a solution, including a solution of NaOH, is primarily dependent on the concentration of the solute and is almost independent of temperature. Explanation:

1. Boiling Point Elevation: When a non-volatile solute, such as NaOH, is dissolved in a solvent, such as water, the boiling point of the solution increases compared to the boiling point of the pure solvent. This phenomenon is known as boiling point elevation.
2. Dependence on Solute Concentration: The extent of boiling point elevation depends mainly on the concentration of the solute particles in the solution, regardless of the temperature or pressure. A higher concentration of solute particles leads to a greater increase in the boiling point of the solution.
3. Independence of Temperature: Boiling point elevation is almost independent of temperature for dilute solutions. This means that the boiling point elevation does not change significantly with changes in temperature within the typical operating range of the solution.
4. Independence of Pressure: Boiling point elevation is also almost independent of pressure, especially for dilute solutions. While changes in pressure can affect the boiling point of the pure solvent (as in the case of altitude changes), the effect on the boiling point elevation of a solution is negligible compared to the effect of solute concentration.