What is your dream holiday
The answer is B. The painting is the most popular in the world is an opinion not an actual fact. It shows bias to the artist.
The best answer here would be D.) Mr.Peat
Rephrase the sentence:
Who draws the best picture?
He draws the best picture.
Now, you need to use this:
He = whoever
Him = whomever
We will have to use whoever.
Whoever draws the best picture will win a prize.
Billy was considered a hero by the many people who had seen his courageous crime-fighting in action.