The direct object pronoun would be "la" because la gasolina is feminine. In a sentence you could say
La compro en la estacion de servicio.
Direct object pronouns are placed before the verb generally.
428.5 onzas de galletas, the question gives you the answer
Cuba is where she was born, it says she's a cuban singer of latin music.
I have a cake.
You have the cookies.
He has the cookies.
She has the cake.
