I need help with this. It’s a fact of fib question so it needs a explanation on why the wrong answers are wrong and why the correct answer is right. Please and thank you.

Researchers were interested in whether relaxation training decreases the number of headaches a person experiences. they randomly assigned 20 participants to a control group or a relaxation training group and noted the change in number of headaches each group reported from the week before training to the week after training. which statistical analysis should be performed to answer the researchers' question?

Need on this geometry question. explain how you did it.

Me. i can't figure out this question. give an explanation too. .