Answer:
The correct answer is - c. adding 10 mL bleach to 90 mL water.
Explanation:
To prepare a effective disinfecting solution to clean the countertops is a bleasce solution of 10% solution of bleach. The ten percent of the bleach solution means there are one volve of bleach and 9 volume of clean water in this solution.
So, preparing the 1/10 or ten percent solution is where adding 10 ml of bleach which is diluted to 90 ml clean water. This diluted solution can be use as disinfecting solution.
