solve pls

Which of the following is / are correct? |- Distribution ratio is the ratio of the total solute concentration in mobile phase to the total solute concentration in stationary phase. 11 - Retention time is the time required for analyte to reach the detector after the sample is injected. III- The selectivity factor is the ratio of the distribution constant of the more strongly retained solute to the distribution constant of less strongly retained solute. Select one: a. Only III O b. I and II c. Only 11 O d. III and III e. Only 1 f. II and