33. Which of the following statement is NOT true? (A) Early tumors may be recognized and destroyed by natural killer cells and T cells. (B) Tumor-rejection antigens help the tumor to escape the immune surveillance. (C) Tumors may avoid immune recognition by expressing inhibitor molecules that repress T cell function. (D) Transforming growth factor-β, interleukin-10, or indoleamine 2,3-dioxygenase play roles in tumor- induced immune suppression.