Final answer:
The best evidence supporting the requirement of high school uniforms is the increase in attendance rates and decrease in behavior incidents after implementing a uniform policy.
Step-by-step explanation:
The piece of evidence that could best support the claim that high school students should be required to wear uniforms is that attendance rates increased, and behavior incidents decreased when uniforms were implemented at a school (option b). This evidence directly relates to the benefits of school uniform policies in improving school environment and discipline, which aligns with the typical goals of such policies. Contrarily, options a and c present points that could actually be used to argue against school uniforms, and while option d provides a positive aspect of school uniforms, it is not as strong or as directly tied to measurable outcomes as the improvements in attendance and behavior.The reference to 'predict what you believe would be the answer' suggests an exercise in hypothesizing or predicting outcomes based on theoretical knowledge or previous results, which is a key skill in the scientific method and important in experimental chemistry.