I would say kidneys or liver
A safer alternative is using a tissue, a q-tip will damage your ear drum
I believe the answer you're looking for is "Meditation."
There are numerous diseases and viruses that can be contracted from airborne germs. Out of the choices given here, the answers will be the flu and strep throat. Both are highly contagious.
Most people start to face new issues at the ages of 11-13 some may gain this at older ages, but it typically starts around that time, some causes of this are: Puberty;School; Problems at home; etc.