Answer: 1. quieres 2. quiero 3. prefiere
Explanation: Here we need to find the right conjugation for the verb "querer" and for the last one the verb "preferir"
The first one is conjugated for "Tú"
The right option here is "Tú quieres".
The second one is for "yo", and the right option is "Yo quiero".
Now, the verb is "preferir"
And the third one is for "Ella", the right option is "Ella prefiere".
The complete conversation would be:
"—Tú quieres la lechuga y yo quiero la cebolla.
—¿Qué prefiere ella?
—El pepinillo.
So the right option is the fourth one: 1. quieres 2. quiero 3. prefiere.