They can be cured. They are caused by bacteria. They are spread to others. They can spread only in winter.
I gave my students this multiple choice question: Which of these best defines communicable diseases?

Only one answer is correct among these 4 choices:
- They can be cured.
- They are caused by bacteria.
- They are spread to others.
- They can spread only in winter.

Could you tell me which one is correct?

They are spread to others.