Two students had a contest to see who could build the fastest boat. Emily spent hours learning about boatbuilding and designing a boat
that would be fast but stable in the water. Aaron spent his time
painting his boat, making it look impressive and flashy, with red flames
along the sides. At the contest, students gathered around to observe
the two boats. They were impressed by the beauty of Aaron's boat.
"Surely that one will be the winner," they said. But Aaron's boat tipped
over and sank almost immediately, while Emily's boat chugged along
to the finish line.
Which statement best expresses a theme of this story?
O A. One should always take pride in looking one's best.
O B. The more time one spends on a task, the better the quality of the
outcome
O C. It is better to cooperate than to try to work alone.
O D. It is more important to focus on the task at hand than to worry
about appearances

C. It is better to cooperate than to try to work alone.

The answer is D, It is more important to focus on the task at hand than to worry  about appearances

Explanation:

That program you use Verified ;)

faulty parallelism is a construction in which two or more parts of a sentence are equivalent in meaning but not grammatically similar in form.

the correct version of this faulty parallelism in the sentence is:

the hikers knew that the hike was six miles, that it usually required the entire day, and it would not be wise to start after 10: 00 a.m.

the problem is the last sentence, the first two have a basic subject+verb+object structure.

so, to give a proper balance to the structure, or better said, to give a parallel structure, we must write a basic s+v+o structure in all three sentences:

the hikers knew that the hike was six miles, that it usually required the entire day, and it would not be wise to start after 10: 00 a.m.

in paragraph 6 of "sinners in the hands of an angry god" by jonathan edwards, he talks about how doing good things alone will not save men from going to hell because they're at the mercy of the will of god. "spiritual reform" provides men with a false sense of safety.