The nurse implements a secondary prevention program for sexually transmitted infections in a local health center. Which outcome indicates that the program was effective?

A. Providing condoms in health clinics is a preventive measure but does not directly indicate the effectiveness of the secondary prevention program. B. Diagnosing at-risk clients early in the disease process indicates successful secondary prevention efforts, as early diagnosis allows for prompt treatment and prevention of further transmission. C. While increasing HPV vaccine prescriptions is a positive outcome, it does not directly reflect the effectiveness of the program in preventing STIs. D. Improved client knowledge is important but does not directly measure the program's effectiveness in preventing STIs.