Carol Rogers, a local millionaire, promises to donate $500,000 to the Springfield Humane Society, which the society plans to use to build a new animal hospital. Based on Carol's promise, the society begins work on the hospital. Carol then backs out of her offer. In this case:.A. Carol may be sued for the money based on promissory estoppel. B. Carol has clearly violated a firm contract. C. Nothing can be done. Carol's donation was a gift. D. Carol will suffer from a bad conscience, but not from any lawsuit.