According to the text, which two diseases do the World Health Organization believe will not exist anywhere on the planet, in the next few years?

The correct answer is B. polio.

Explanation: The World Health Organization (WHO) has made significant progress in eradicating polio through vaccination efforts worldwide. They believe that with continued efforts, polio could potentially be eliminated in the near future. Tuberculosis, diarrhea, typhoid, and malaria still pose significant challenges and are unlikely to be eradicated entirely in the near future.