This question is about "A Quick Note on Getting Better at Difficult Things"
Answer:
B to encourage people to keep working hard, even if something is difficult
Step-by-step explanation:
The text has a very motivational content, where the author shows that no difficulty will last forever, if we are endeavored to fight them. Although this fight is tiring and often hopeless, the author shows how the reward for winning it will be pleasant and will bring happiness, strength and strength to those who do not give up.
Based on this, we can say that the main purpose of the author is to write a text where he encourages people to continue working hard, even if it is something difficult.