Hello! The best answer would be C - Colds because bacteria can reproduce and spread rapidly, which is why a cold sometimes develops fast. As for the others, your body is just adjusting to the weather with A, B is a sexually transmitted disease which is caused from contact with another through sex, D is caused by sweets/certain foods that break down your teeth. I hope I helped you!! Have a great day!!
The answer, I believe, is all of the above.
Hope this helps!!
DNA replication occurs in the synthesis stage and is followed by the gap 2 stage