The correct answer is "The World Health Organization" (WHO).
The World Health Organization is a specialized agency of the United Nations which is focused on assessing public health issues and assuring "the attainment of all people of the highest possible level of health". It was established on April 7th, 1948.
The WHO is the organization in charge of granting professional advice and medical support to countries or regions who are undergoing an epidemic in order to prevent it to become a pandemic.