City Q has access to abundant fresh water that it draws from undergrou

The argument tell us that despite enough water for all for several years , the residents to city Q are forced to cutdown or reduce the usage of water .

To resolve this paradox , we need to look for an answer choice that will address both the issues.

(A) The supply of water in the springs is greater at some times of the year than at others.
This choice fails to address the issue highlighted in the argument. When the supply of water is more or less is insignificant to the argument. The argument wants us to reason why residents are forced to cut down on usage despite adequate ground water supply for several years. OUT OF SCOPE .

(B) Residents of City Q rely heavily on water for their cooking and cleaning.
How the residents of city Q use the water available to them is not mentioned anywhere in the argument . OUT OF SCOPE.

(C) City Q has not sought out alternative water sources.
Again OUT OF SCOPE .

(D) Most of the water in the springs is allocated to industrial uses and not drinking.
If most of the water in the springs is allocated to industrial uses then the quantity of water available to the resident of City Q for domestic usage is less and hence they will have to cut down on water usage to sustain for longer ….CORRECT

(E) City Q has yet to completely tap into all of its underground springs.

Out Of Scope

I think both B and D are okay.
For B, water consumption includes not only drinking, but also other usages, such as cooking and cleaning. Thus water in the springs is NOT necessarily enough for heavy consumption of cooking and cleaning, although it is more than enough water to satisfy the demand for drinking water.
So B can also explain why should cut off water consumption. Discussion appreciated.

According to current paradox, the city has water in springs but let residents are asked to cut down on the usage, what must be the reason?

(A) The supply of water in the springs is greater at some times of the year than at others. - Not relevant, we are talking about total water we already have.

(B) Residents of City Q rely heavily on water for their cooking and cleaning. - The allocation and usage of water is not relevant here, it's the water available vs consumption.

(C) City Q has not sought out alternative water sources. - If it will sought out, we may find more water, not relevant.

(D) Most of the water in the springs is allocated to industrial uses and not drinking. - correct, this choice resolves the difference of water avaialble vs water available for consumption.

(E) City Q has yet to completely tap into all of its underground springs. - If the city does find more water, there may be no need of reduction of consumption. Not relevant.