Which of the following statements, with reference to a solution, are correct?
(A) The osmotic pressure of the solution is proportional to the molarity of the solute.
(B) The elevation of the boiling point (\(\Delta T_b\)) is directly proportional to the molal concentration of the solute in a solution.
(C) The unit of \(K_b\) is \(\mathrm{K} \mathrm{kg}^{-1} \mathrm{~mol}^{-1}\).
(D) \(\Delta T_b=T_b^0-T_b\).
Choose the correct answer from the options given below:

Apply the relevant identity from the chapter and substitute the values established in the previous step, keeping the original constraint in view.

Use the simplified expression to isolate the unknown, then plug the result back into the question setup to confirm the working is internally consistent.

Cross-check against a boundary or limiting case. Both the dimensional balance and the qualitative behaviour at the extreme should agree with the candidate answer.

Combine the steps above to identify the correct option. The remaining choices each fail at least one of the consistency, dimensional, or boundary checks.