Question

read the passage from president barack obamas back-to-school remarks. maybe you could be a good writer—maybe even good enough to write a book or articles in a newspaper—but you might not know it until you write a paper for your english class. maybe you could be an innovator or an inventor—maybe even good enough to come up with the next iphone or a new medicine or vaccine—but you might not know it until you do a project for your science class. in this section of the speech, the purpose of the parallel structure is to help obama ○ emphasize his belief in the importance of being able to write well. ○ explain his thoughts on the best classes to take for a good education. ○ prove his point by spelling out the options available with an education. ○ strengthen his argument that more scientists are needed in the workforce.

Explanation:

The parallel structure uses two matching "Maybe you could be...—but you might not know it until..." clauses. Each clause outlines a potential career/skill (writer, innovator/inventor) that can be discovered through school work. This structure lists out the different possibilities that education can unlock, spelling out the options available to students via their classes. The other options are too narrow: the first only focuses on writing, the second doesn't discuss "best classes", and the fourth only focuses on scientists, while the passage covers multiple fields.

Answer:

prove his point by spelling out the options available with an education.