Galactic Quest 2: The Search for More Monet's Water Lilies

After saving the galaxy from certain doom in the first installment, you're now on a mission to find more Water Lilies for the Galactic Museum of Art. Because, you know, one can never have too many.

You are currently on the planet "Zorgon-6" where the locals have heard rumors of a hidden lily patch. They'll only tell you where to find it if you answer their trivia question:

What is the most expensive art style in the galaxy? (Hint: It involves a lot of rectangles)