Art: profound or pointless?

IMAGINE this: Your best friend has just bought a piece of art. It cost him $200,000 and he wants to know what you think of it.

All you see before you is a plain white canvas measuring 1.5m by 1.2m. Okay, okay, if you squint really hard, you can see some fine white lines running diagonally.

Do you tell your friend that (a) it's a masterpiece and a good investment; (b) it's not your place to judge as beauty is in the eye of the beholder; or (c) it's a piece of cr*p and he's been swindled of his hard-earned money?