The costs of investing in mutual funds may include: A. sales charges (front-end loads), redemption fees (back-end loads), operating expenses, and 13D charges. B. sales charges (front-end loads), redemption fees (back-end loads), operating expenses, and 12-b 1 charges. C. sales charges (front-end loads), redemption fees (back-end loads), operating expenses, and 10K and 8K charges and performance fees. D. sales charges (front-end loads), redemption fees (back-end loads), operating expenses, and 13D charges and performance fees.