Read this sentence:
i couldn't tell how to replace the headlight from reading the car's manual because the directions were totally ambiguous.
what resource could you use to find the meaning of ambiguous?
almanac
thesaurus
dictionary
encyclopedia

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.