Two coincidental lines intersect each other at infinite number of point true or false

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?

Can someone check if i did this right since i really want to make sure it’s correct. if you do you so much

Icould really use some with this question.