Answer: a. Short term
Limiting factor is a factor which limits the growth, abundance and distribution of a population of species in an area or ecosystem. A potable water is a water that can be used for drinking purpose. The lack of potable water in an area can be a short term limiting factor because the technology can be used to purify the water obtained from nearby water source like river, lakes and ponds. Appropriate transportation facilities can help in availing water from other regions.