It is A. Quanta, have a nice day!!
A. density
<span>Reaction rate increases with concentration.</span>
The freezing point of water is 0° C. The Celsius (centigrade) scale is based off of water, with the freezing point at 0° and the boiling point at 100°. (Google will probably tell you this in 10 seconds, then you wouldn't have had to wait 7 hours!)