The CDC's recommendation for the initial administration of HPV vaccine in males is:

Rationale: A. The CDC recommends that the HPV vaccine series be initiated in males at ages 11–12 years for optimal immunogenic response and before potential exposure to HPV through sexual activity. B. While vaccination between ages 13 and 16 is still effective, it is considered a catch-up period rather than the recommended age for routine initiation. C. Ages 13–26 include catch-up vaccination for those who were not vaccinated earlier, but this is not the routine initial recommendation. D. Age 8–9 is earlier than the recommended age for HPV vaccination and is generally not indicated unless specific high-risk factors are present.