Pretty sure it's 2 because the words Congress and Avenue should be capitalised.
The underlined pronoun <em>who </em>is used as a D) subject in this sentence. The subject is the doer of the action, the one who left mittens on the ground, in this case.
The answer is subcordinate
The way i do it is cover up the other words and read the underlined part alone and see if it makes sense
a alligator tried to kill me and my dad?
