If you are feeling very anxious about delivering a speech, the most effective response is to practice your presentation until you are comfortable with it
Answer: C
Explanation
As the adage goes, practice makes a man perfect.
All skills can be achieved if there is a persistent disciplined practice behind it.
Though the other points can ease a person, this point dominates from the rest.
Practice improves efficiency, it makes the senses and brain to adapt to your mission.
Through practice, new skills can be achieved.