Plzz help!! I'll mark brainliest​

Tu bois du lait is the right answer
Tu bois de l’eau would be the right answer if it was " lait " instead of " eau "
(lait means milk and eau means water)

Tu boivent de l’eau, tu boivent du lait are not correct at all, you can forget these two

Tu boivent de la lait. :)

It depends : )
if the narrator participates in the story (it’s a character of the story) then yes.
but if the narrator does’nt participate in the story (the narrator does not have a character) then no.