Ais a chemical solution that keeps ph within normal limits by absorbing excess hydrogen, or h+, ions and hydroxide, or oh-, ions.

Buffer.

Explanation:

A buffer solution is a solution made out of a weak acid/base and its conjulgated base/acid. This kind of solution is special because it is resistent so pH change because it can react with acids and with bases, thus it keep pH withing a determined range as long as it is not fully consumed by excess adition of acid/base.

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.

the correct answer would be d. hope this !