What is the definition of portable water?

The correct definition of portable water refers specifically to water that is safe and suitable for human consumption and has been treated to meet health standards. Option A highlights that this water undergoes treatment by preventative medicine, which typically includes processes like filtration, chlorination, and testing to ensure it is free from harmful contaminants, pathogens, and pollutants, making it drinkable.

In contrast, the other options do not meet the criteria for portable water. Unfit water cannot be consumed safely and would not be termed portable. Water from untreated wells can pose health risks due to potential contamination and does not ensure safety for drinking. Rainfall, while a natural source of water, may not be clean or safe without proper treatment and can also contain pollutants. Thus, only the definition related to treatment by preventative medicine accurately reflects what portable water signifies in terms of safety for human use.