D...a lack of interest in activities that used to be important to him or her.
Answer:
D.) Enact measures to test city pools more frequently.
Answer:
I dont know sorry put ask someone else
Explanation:
The answer is B. chemicals.
the reason its b is because A= bacteria but u have to clean the bacteria in the water so its not A and its not c. becouse that will be just turning the ice into water .so the answer is b. becouse we use chemicals everyday to get rid of bacteria and waste