pH is defined as the negative log of Hydronium Ion concentration.
So, in order to find the pH of vinegar, we find the negative log of its hydronium ion concentration.
![pH=-log[ H_(3)O^(+)] \\ \\ pH=-log(1.6 * 10^(-3)) \\ \\ pH=2.8](https://img.qammunity.org/2019/formulas/chemistry/college/7cjidgmy6eumbyz50vpx70eh6reoms07og.png)
So, the pH of given vinegar solution will be 2.8.
Therefore, the answer to this question is option B