Which sentence presents an unsound argument? A. I enjoy going to the dentist because she helps me take care of my teeth. B. I have to find a new dentist because my former dentist is retired. C. My dentist is the best because he is my neighbor. D. Dentists are often not popular with children.

An unsound argument is a type of argument in which the main argument might be true but the premise or the previous reason or proposition that support this argument is false or both the argument and the premise are false, which makes the argument to claim something that is not valid or real. This usually happens because there are issues in the process of deduction or reasoning which led to invalid assumptions or conclusions, this can be seen in the case of the argument " My dentist is the best because he is my neighbor" as both parts of the argument are not connected and there is an invalid assumption. This can be explained as being my neighbor does not make it the best dentist, which means the argument is stating something that is not true as the premise is fals, which makes this argument an unsound argument.