Answer:
A. According to the board of education, “school uniforms improve behavior, build school spirit, and develop a student’s sense of belonging.”
Explanation:
A claim, which in this case is "School uniforms should be mandatory for all students" is a statement that expresses the position of someone regarding some topic, situation or issue. However, for any claim to be valid it requires reliable and relevant evidence such as facts, statistics or reference to external sources. In terms of effectiveness (how strong an evidence is) and reliability, which is whether a source can be trusted or not, expert's opinions, and research studies are preferred over informal ones such as examples, anecdotes or people's opinion.