Question

why were towers designed in the middle era? so people could see attackers coming during war to pump water from deep underground to grind wheat into flour much faster

Explanation:

In the Middle Ages, towers (like those in castles) were primarily for defensive purposes. Being elevated, they allowed people to have a better vantage point to spot attackers approaching during conflicts. The other options relate to water - pumping (which is not a main function of these towers) and grinding wheat (a function of windmills or watermills, not typical tower design).

Answer:

so people could see attackers coming during war