She's applying emphasis onto the word. Christie wants the word dramatic to really be out there. Christie is implying that __ is very dramatic. This repetition makes the word stick in our heads as the main focus.
The correct answer would be 3, gasta as you are conjugating the verb "gastar" for ella as the word "hermana" means sister and is feminine.
Source(s): I speak Spanish. :)
Hope this helped; have a great day!
