Which of the following is a regional office of WHO?

The correct choice indicates that Washington, D.C. is indeed a regional office of the World Health Organization (WHO) representing the Americas (AMRO). This regional office plays a crucial role in coordinating public health initiatives, responding to health emergencies, and providing guidance to countries within the Americas on health issues. The focus of WHO's AMRO office includes addressing specific health challenges relevant to the regions, promoting health policies, and supporting countries in strengthening their health systems.

The other options present regional representations that are either inaccurately labeled or do not exist as WHO regional offices. For example, Tokyo is associated with the Western Pacific Region (WPRO), not SEARO (Southeast Asia Region). Sydney is not a representation of EURO (European Region), as the Euro office is based in Copenhagen. Bogotá indeed represents the Pan American Health Organization (PAHO), but PAHO functions as the regional office for the Americas under WHO rather than a directly named regional WHO office. Understanding these distinctions is critical for anyone studying global health and the structural organization of the WHO.