The answer is false to your question.
C. When you take a step, the ground pushes back on your foot with the same amount of force. If it pushed back with less, your foot would go through the floor; if it pushed back with more, it would actually push your foot off the ground. But they're in opposite directions; your foot pushes down, while the ground pushes up.
Hope this helps!
The enzyme will likely be less affective or more affective, however, it depends on what the perfect temps tire is. since this sounds like it is lowering its temp from the “ideal range”, the enzyme will be less effective!