The details in the excerpt show readers that Buwan

expository writing is one of the most common types of writing.

use the headings to create an overview of the main points.

2b2t

explanation:

2b2t

i believe the answer is: b. mr. head had a long, tube-like face with a rounded open jaw and a short depressed nose.

this is because in the un-revised sentence it said that mr. heads face was long and tube-like, and he had a rounded open jaw. this is not a very grammatically correct because of how it seems to drag on with the and, replaced with, with, makes it sound more fluent in the description.