Suppose the major soft drink companies develop vending machines for canned and bottled drinks that ...

Suppose the major soft drink companies develop vending machines for canned and bottled drinks that can determine your maximum willingness-to-pay for a drink, and the machine charges you that price when you purchase a drink.  If this were possible, the consumer surplus in the vended soft drink market would be:
A) positive because consumer surplus equals consumer expenditures in this case.
B) positive because the market demand curve is perfectly inelastic in this case.
C) negative because people are not actually willing to pay their maximum value for the product.
D) zero because all surplus value is captured by the seller.