Which type of writing is most likely to require the use of academic vocabulary? a thank-you letter to your aunt
a grocery job application
an email to your friend in Australia
an analysis of a poem

the type of writing most likely to require the use of academic vocabulary is a grocery job application.

Explanation:

all other choices would most likely be written in a casual way. i mean, when you text your friend would you use big vocabulary words or type in complete sentences? probably not. for a job application, however, you would want to seem proper and professional, so you'd most likely use academic vocabulary.

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.