1. es 2. son 3. es 4. sois 5. soy 6. es 7. son 8. es 9. sois 10. son 11. es 12. son 13. eres 14. es 15. soy 16. somos 17. sois 18. es 19. son 20. son 21. son 22. es 23. es 24. son 25. es
The answer would be A) Intensity. Because, You are pushing your body to get in all the training it needs in a short amount of time by intensifying the workout.