Which of these is the best definition of a primary source?

Plss me i need hrelp i will give you 12 pionts. a student is writing a blog claiming that school uniforms are a good idea. which sentence provides evidence to support this claim? a: many students are against wearing school uniforms because they think they will look silly. b: a recent study found that students who wear uniforms are more focused during class. c: a recent poll found that only ten percent of teachers are in favor of school uniforms. d: many parents worry that school uniforms will be more expensive than regular clothing.