A study showed that people who take a B12 vitamin daily have a significantly better chance of protecting against Alzheimer's dis
ease than those who did not take the vitamin daily. Which of the following statements is/are correct? I. This study provides evidence that taking a B12 vitamin daily contributes to protecting against Alzheimer's disease.
II. The general health consciousness of people who take B12 vitamins could be a confounding variable.
III. This is an observational study and not an experiment.
a. l only
b. III only
c. l and II only
d. ll and III only
e. I, II, and III
The Identity Property of Addition states that the sum of any number and zero will always be the first number. So -6 + 0 = -6 shows the Identity Property of Addition.
