Final answer:
To investigate the effects of anions on pH, test the salts CH3NH3NO3 and KClO.
Step-by-step explanation:
To investigate the effects of anions on pH, you should test the salts in the set (c) CH3NH3NO3 and (e) KClO. When these salts dissociate in water, they produce anions that can affect the pH of the solution.