What is the purpose of including phenol red in triple sugar

Last updated: 7/15/2022

What is the purpose of including phenol red in triple sugar iron (TSI) medium? a. Phenol red ferments the sugars. b. Phenol red can be reduced to hydrogen sulfide. c. Phenol red is a pH indicator. d. Phenol red inhibits catalase. e. Phenol red undergoes fermentation.