4 is A because of ir → vaya; vayan to go → (you, formal) go; (you, pl.) go
5 is C because of ser → sea; sean to be (permanent characteristics or qualities) → (you, formal) be; (you, pl.) be
I got this straight from my notes,
I hope it helps
<span>Necesita would be the correct form of Necesitar
</span>
21. Tendras
22. estrellas
23. saldria
24. dirias
25. de moda
