Which Statement Accurately Describes How Water Can Be Rendered Safe

Which statement accurately describes how water can be rendered safe for drinking in the event of a disruption of service?

A) Allow water to sit for 24 hours before using.
B) Boil water for 3 to 5 minutes.
C) Add 1 mL (16 drops) of household bleach to a gallon of water and let it stand for 30 minutes.
D) Drain water from hot water heaters.
E) Pour water through several layers of cotton towels.