A solution that contains the maximum amount of solute that is soluble at a given temperature is said to be saturated.
Explanation:
A Saturated solution is one that contains as much (i.e maximum) solute as it can dissolve at that temperature in the presence of undissolved solute particles.
For instance: if a given volume of water can only dissolve a certain amount of salt in it at room temperature, then, more salt added will not dissolve.
Acceleration is when something is being moved forward or back, motion is just movement, friction is two or more things rubbing together, so the answer should be B. gravity