Friends, parents, wife/husband, siblings, teachers.
Answer and Explanation:
A resource that can be used to evaluate your statement about the effectiveness of toothpaste is the comparison between the effect it has on teeth, with the effect of an ordinary toothpaste. You could do this by bringing your family members together and separating them into two groups. One group would use regular toothpaste and the other group would use toothpaste which you believe actually whitens your teeth. The groups were to use the same toothpaste for a month and were to take pictures of the teeth each week. These photos would help you compare the whitening effect of toothpaste and thus prove that your toothpaste is efficient in whitening teeth, as it promises.
The answer to this question is : D.
