1.) Los niños so bajos.
2.) Los niños so altos.
3.) Los niños son altos.
4.)Los niños son inteligentes.
All of the sentences have something incorrect some forget the tilde and some have misspelled words. This is how all the sentence should look if they were correct.
Tu because If you put Mi or mis son rojos it says my are red which dosen't really make sense. Since you put tu in front of son (plual) it would be they are red.
C, Conoce, La.
because Pamela is female so it has to end in "a"