Answer:
4. "You try to set down what you see find out your error, and correct it. You need not play tricks or purposely mistakes with all your pains, you are still far short of the mark."
Step-by-step explanation:
The line from the passage that best represents the author's viewpoint on the importance of honesty in painting is the fourth option "You try to set down what you see find out your error, and correct it. You need not play tricks or purposely mistakes with all your pains, you are still far short of the mark." which says that when painting, it is important to find errors and correct them and not intentionally make mistakes.