Correct Answer - Option 2 : Both I and II follow.
The logic that follows here is:
I. The residents in these wards should reduce the use of water on Friday.
As the repairing work of the main lines is carried out 50% of the water supply is already affected in both the wards. If the residents reduce the use of water then water will be equally distributed to all the residents so that they can at least fulfill their daily requirements of water.
II. The residents in these wards should store some water on the previous day.
Storage of water is always a good practice. If the residents of the ward stored some amount of water on the previous day then it would help them to compensate for the shortage of water on the next day.
Hence, Both conclusions I and II follow.