Answer:
A. Thou are great at school
C. Thy pants are too tight.
Explanation:
Granted these are the safest options, so lets use the process of elimination
B. Thee is a cutie.
Thee is an archaic or dialect form of you, as the singular object of a verb or preposition.
So let's replace it in the sentence
You is a cutie, now that doesn't make sense with the sentence we are given
D. When thine looks are ugly thine must eat chicken nuggets.
Thine is an archaic form of yours; the thing or things belonging to or associated with thee.
Now lets replace it in the sentence
When yours looks are ugly yours must eat chicken nuggets, again that sentence makes no sense even if we replace thine with your not yours
I'm sorry I couldn't give you a specific answer but I hope this cleared up some of it for you
