Question

which challenges do countries face in limiting the spread of communicable diseases?
lack of available healthy food
increase of worldwide travel
decrease of available clean water
increase in migration of infected animals

Explanation:

To determine the challenge countries face in limiting communicable disease spread, we analyze each option:

• "Lack of available healthy food" relates to nutrition/health but not directly to disease spread mechanisms.
• "Increase of worldwide travel" facilitates the rapid movement of people, allowing infected individuals to spread diseases across regions, making it a key challenge.
• "Decrease of available clean water" affects hygiene/health but is more about water - related health issues rather than disease spread dynamics.
• "Increase in migration of infected animals" is less common and impactful on a global scale compared to human - to - human spread via travel.

Answer:

B. increase of worldwide travel