The correct answer is B. 2.0M of HCl.

Here's why:

- HCl (hydrochloric acid) is a strong acid, which means it completely dissociates in water to produce H\(^+\) ions and Cl\(^-\) ions.

- The concentration of HCl is directly related to its ability to conduct electricity. A higher concentration of HCl means more ions are available to carry electrical charge.

- Between options A and B, the 2.0M HCl solution has a higher concentration of ions, making it a better conductor of electricity.

Ethanoic acid (CH\(_3\)COOH), on the other hand, is a weak acid, which means it only partially dissociates in water. As a result, it produces fewer ions and is a poorer conductor of electricity compared to HCl.

So, even though option D has a higher concentration of ethanoic acid, it still won't conduct as much electricity as the 2.0M HCl solution.