The measures (A) have contributed to the effort to preserve biodiversity and (B) put an end to the (C) illegally use and trafficking of wildlife (D) across the country

Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs correction in each of the following questions.

The measures (A) have contributed to the effort to preserve biodiversity and (B) put an end to the (C) illegally use and trafficking of wildlife (D) across the country.