The correct answer is D) The take cabin space makes it easier for the disease to spread.
Considering the dangers associated with spreading disease, people who were affected by communicable diseases are told not to travel on airplanes because "The take cabin space makes it easier for the disease to spread."
When you travel by airplane, the space in the cabin is so tight and the ventilation process is slow. Depending on the size of the plane, you are traveling with other 50 to 180 passengers who probably carry cold or throat viruses. If you spend one, two, three hours of flight, people are breathing everybody's breath. That is why it is recommended for these kinds of people not to travel by plane.