Hello!
The correct answer is C. "People who support animal testing are crazy."
This is an example of an ad hominem fallacy because the thesis states that animal testing is valuable, which insinuates that the person making the claim believes in animal testing. By claiming that "people who support animal testing are crazy" is making a statement about the person himself rather than about the argument. The sentence is stating that the person who supports animal testing is crazy rather than explaining a counter-argument about the topic.
I hope this helps you! Have a lovely day!
- Mal
