C) floatation
Floatation<span> is a separation process in which </span>minerals<span> that are valuable are separated from worthless material or other valuable </span>minerals<span> by inducing them to gather in and on the surface of a froth layer</span>
The relflex arc is basically a connection of nerves in your nervous system that doesnt pass through the brain.
The right answer is A. An impact of changing scientific knowledge on society