Answer:
A) Mononucleosis
Explanation:
Mononucleosis is an infection, more common in children than adults. the general symptoms are fever, swollen neck lymph nodes, between others. Sometimes even affecting other organs of the body, like the liver.
The guilty of all this infection is the Epstein–Barr virus that it is primarily spread by saliva. Since its a really contagious bacteria can be easily transmitted by an infected person who uses or drink from the water bottle to other ones.