Answer:
4
Explanation:
4, because an unclear pronoun is when they, this, that, it refers more than one time in a sentence, so the correct answer is 4. 4 has "they" and "that" together in one sentence.
You can use the words 'used to' and 'boarded' as past tense.
I believe it is option A. that is what I would go with.
Show me the two sentences do I could answer
