I learned about this at my school I think the answer is A because it was the only one I remember
Vertical
1. Horario
2. Ciencias
4.Antes
5.(any persons name can go here)
8. Matemáticas
12.Examen
14.Cuantos
15. Veintitrés
16. Difícil
17.Veintiuno
19. Español
21. y media