What is the core responsibility of the World Health Organization (WHO)?

The core responsibility of the World Health Organization (WHO) is the management of the global regime for control of the international spread of disease. This involves a range of activities aimed at preventing, managing, and controlling health threats that cross national borders. The WHO plays a critical role in coordinating international responses to health emergencies, such as outbreaks of infectious diseases, and provides guidance and support to countries in their public health efforts.

This function includes monitoring and assessing health trends, establishing protocols for disease control, and promoting health standards internationally. The organization's role is paramount in organizing resources, facilitating research, and disseminating information related to disease prevention and control, thus impacting global health security.

While the other options may pertain to significant aspects of public health and management, they do not capture the primary role of the WHO, which is specifically focused on the prevention and management of diseases on a global scale. The WHO does not primarily manage communications or oversee international health insurance systems; these are outside the scope of its core mission.