A study of 267 college students investigated the impact of smartphones on student connectedness and out-of-class involvement. One finding showed that students reporting a higher perceived usefulness of smartphones in educational settings used their smartphone a higher number of times to send or read email for class purposes than students reporting a lower perceived usefulness of smartphones in educational settings. Does the study suggest that perceived usefulness of smartphones in educational settings and use of smartphones for class purposes are positively correlated or negatively correlated?

a. The study suggests a negative correlation because the study shows that as perceived usefulness of smartphones increases, the number of times smartphones are used to send or read email for class purposes tends to decrease.
b. The study suggests a positive correlation because the study shows that as perceived usefulness of smartphones increases, the number of times smartphones are used to send or read email for class purposes tends to increase.
c. The study suggests a negative correlation because the study shows that as perceived usefulness of smartphones increases, the number of times smartphones are used to send or read email for class purposes tends to increase.
d. The study suggests a positive correlation because the study shows that as perceived usefulness of smartphones increases, the number of times smartphones are used to send or read email for class purposes tends to decrease.