Answer:
Gisella is using the primacy principle.
Step-by-step explanation:
As Gisella knows that the audience is against her position, she presents her main argument for students taking two years of a foreign language before graduating at the beginning of her speech so that the audience remembers the main point of taking these classes.
In other words, the primacy principle states that a person mostly remembers what the speaker says at the beginning of the speech, and the person will retain less information as time goes by. That is why Gisella must present her main argument at the beginning of the speech.