(i) K kg mol^-1 or K (molality)^-1

(ii) mol kg K^-1 or K^-1(molality)

(iii) kg mol^-1 K^-1 or K^-1(molality)^-1

(iv) K mol kg^-1 or K (molality)

Correct Answer: (i) K kg mol^-1 or K (molality)^-1

Explanation: The unit of ebulioscopic constant is K kg mol^-1 or K (molality)^-1