The answer to your problem is c
With doctors and nurses as well as patients (or parents of the patients) who understand the medical terminology you are using
I think the answer is c. Thats what my brother does with his kids
They can if they want to, but if they do they will infect whoever they are doing it with. No one can stop them. But if you are looking for a definitive answer then no, it is not okay at all because of the risk they are putting other people at. Especially because STDs are with you forever, they never go away.
Hope this helps!!