The correct answer is B) proper voice, tone, and word choice.
The other options of the question were A) proper word choice and viewpoint. C) proper thesis, voice, and word tone. D) proper thesis and voice.
The option that describes the best writing style of an argumentative essay is proper voice, tone, and word choice.
When we are about to write an argumentative essay, you first need to do your research about the topic at hand. Then you will be able to decide if the evidence is valid and appropriate for your essay. If you are ready, you need to establish your position about the topic to start your argumentations and be specific.