Answer:
B. Surface of the skin
Explanation:
If we had mucous on the surface of our skin then our skin would have a thick slippery fluid like substance on it all of the time. Mucuos membranes are present in the digestive tract, mouth, lungs, and more.
For every action there is an opposite and equal reaction
Every object not in motion stays that way unless acted upon. Any object in motion will stay at the same speed unless acted upon
The force acting on an object is equal to the mass of that object times its acceleration