Between 2014 and 2016, more than 25,000 children in Flint, Michigan, drank water that was contaminated with lead from lead pipes. During this time, the city claimed the water was safe to drink. Which of these actions could the city have taken to ensure that the drinking water was free from lead?

Regularly test the water in residents' homes.

Explanation:

The only way to know if tap water contains lead is to do tests to determine the levels of that metal in the water. Therefore, the state is under an obligation to constantly conduct such tests in the resident´s homes and thus determine whether the water supplied is fit for human consumption.  

The state after the tests must guarantee the population the treatment of the water to reduce the levels of lead. The main pipes that contain lead pipes must be changed, as well as those parts of the service connections made of lead.

the best answer is d because the strong cohesion is caused by the ability of water molecules to undergo hydrogen bonding.

a is incorrect because when water solidifies, it becomes   ice, which expands and occupies a bigger volume for the same mass of water in its liquid state.

b is incorrect because water has high surface tension. besides bonding to itself it hydrogen bonds to other molecules at the top decreasing possibility for breaking of attractive forces.

c is incorrect because the water molecule has oxygen which is highly electronegative and so pulls the electron pair towards itself creating a dipole moment, making the molecule polar.

e is incorrect because water has strong adhesion, ability to stick to other molecules such as glass because of this molecules having stronger hydrogen bonding than water.

what is the question?