An investor spends $300,000 starting a shoe store. The business operates for a year and is failing. The manager of the store indicates that another investment of $200,000 could save the business. The investor should... C Invest more since she's already invested a lot of money and doesn't want her initial investment to go to waste Invest because she believes in the talent of the manager Never invest more money Invest only if the benefit of doing so will exceed her opportunity cost