Andrew paid $30 to buy a potato cannon, a cylinder that shoots potatoes hundreds of feet. he was willing to pay $45. when andrew's friend nick learns that andrew bought a potato cannon, he asks andrew if he will sell it for $60, and andrew agrees, since he would have sold it for $45. nick is thrilled, since he would have paid andrew up to $80 for the cannon. andrew is also delighted.

what is andrew's original consumer surplus?
$15
$20
$30
$50