Answer:
On average, school uniforms cost $150 a year, which is much less than the average spent on back-to-school clothes.
Step-by-step explanation:
As seen in the given passage, the author's main claim is that the introduction and use of uniforms in schools is a much better option for both parents and the students. The uniforms will enable the students to not only dress the same but also give them much more time to focus on their studies.
And in the argument that mandatory school uniforms are the basis of equality in a school, the author states that this move "save(s) money and time". This argument can be supported by the statement that "financial investment in uniforms at the beginning of the school year is far more economical than the purchase of an entire wardrobe of designer clothes and trendy styles." So, the fact that spending $150 a year for school uniforms is much more economical than the average spending on back-to-school clothes best supports the author's claim/ position.
Thus, the correct answer is the first option.