This is gravity.
Gravity is a force that is exerted on all objects on earth. The greater the mass, the greater the force of gravity is on an object.
Explanation:
Make an observation about a phenomenon (qualitative and/or quantitative)
Ask a research question.
Hypothesize a possible answer for your question.
Create a procedure to test your hypothesis.
Identify what you are testing.
Identify your control group/experimental group.
The answer is C.<span>The shell protects the crab from predators</span>
