Caroline Agreed to Purchase Organic Hemp Fabric from an Ontario

Caroline agreed to purchase organic hemp fabric from an Ontario manufacturer.While making an inquiry to purchase organic dyes from a Manitoba producer,she learned they offered a superior organic hemp fabric at a much lower price.Knowledge of which of the following legal principles would immediately let Caroline know she made a costly error?

A) Parties must be informed as to adequacy of price, as it is usually unopen to challenge.
B) The consideration to be given for each party's duties is the other party's duties.
C) Parties must pay the price for a promise before they can sue when it is broken.
D) The traditional perspective that alteration of a pre-existing duty is enforceable.