Which piece of evidence could persuade a reader to support a claim that middle-school students should be required to wear uniforms?

In a school district that recently made school uniforms a requirement, attendance rates and grades have increased.
In a school district that recently made school uniforms a requirement, attendance rates and grades have increased.

Compared to the cost of regular clothes, the cost of uniforms is often quite less.
Compared to the cost of regular clothes, the cost of uniforms is often quite less.

When everyone looks the same in their uniforms, students begin to lose their uniqueness.
When everyone looks the same in their uniforms, students begin to lose their uniqueness.

School uniforms can be ordered online, which is much easier than going to a store.

School uniforms can be ordered online, which is much easier than going to a store.

If true then:

In a school district that recently made school uniforms a requirement, attendance rates and grades have increased.

This piece of evidence could persuade a reader to support the claim that middle-school students should be required to wear uniforms because it shows a correlation between the implementation of uniforms and positive outcomes such as increased attendance rates and grades.