A. salido is the correct past participle for the Spanish verb salir.
Past participle is formed by adding the suffixes -ado, or -ido to the root of the verb, depending on the last letter of the verb.
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.
encantado, vosotros, dinero, libro
1- se
2-nos
3-me
4-me
5-me
6-me
7-te
8-se
9-se
I hope it helps you:)