I think b. Proteins are polymers of amino acids is the correct answer
The pyloric sphincter is compose of smooth muscle and is located between the pylorus in the stomach and duodenum of the small intestine. In digestion, it serves as a valve controlling the flow of food thus it prevents the contents of small intestine backing up into the stomach.
Solution :
1. They can be reproduced on a human timescale --- renewable resources
2. They take millions of years to form -- non renewable resources
3. They are produced naturally -- renewable resources
4. They are extracted by mining -- non renewable resources
5. Their use as an energy source is increasing because they reduce pollution -- renewable resources.
Natural disasters can cause great damage on the environment, property, wildlife and human health. These events may include earthquakes, floods, hurricanes, tornadoes, tsunamis, landslides, wildfires, volcanic eruptions, and extreme temperatures.