What is the tallest mountain?

Question 1:  What is the tallest mountain in the world?
Question 2: Which famous artist painted the Mona Lisa?
Question 3: In the world of science, what does the acronym "DNA" stand for?
Question 4: Which country is the largest producer of coffee in the world?
Question 5: In honor of World Penguin Day, how many species of penguin are there?