<span>C. the bus broke down, so we had to walk.</span>
Based on the given sentence above, the error that I can find is the incorrect use of the pronoun "their". Looking at the sentence, the subject is "One of your students", this means only one, and not all the students. Therefore, this should take a singular pronoun. So the correct sentence would be "One of your students left his or her book on the table." So the answer for this would be option A. Hope this helps.
The use of parenthesis is to include something in a sentence that isn't necessary to the sentence. Meaning, if taken out, the sentence would still make sense.
So, for each sentence, take out what is in parenthesis and see of the sentence still makes sense.
A. The cowboy hat <span>it skiing fit perfectly.
- This does not make sense, so it is incorrect
B. </span><span> I planned to wear it skiing fit perfectly.
- Though this ALMOST makes sense, it is missing the main subject, which is the cowboy hat
C. </span>The cowboy hat <span>fit perfectly.
- Makes sense!!
D. </span><span>The cowboy hat I planned to wear it skiing.
- This is missing the main verb. So, now the sentence is incomplete.
The answer is C :)</span>
I believe the answer is D.) English sonnet . I hope this helped .