State the conclusion based on the results of the test.
According to the report, the mean monthly cell phone bill was $\$ 49.62$ three years ago. A researcher suspects that the mean monthly cell phone bill is higher today. The null hypothesis is not rejected.

Choose the correct answer below.
A. There is sufficient evidence to conclude that the mean monthly cell phone bill is higher than its level three years ago of $\$ 49.62$.
B. There is not sufficient evidence to conclude that the mean monthly cell phone bill is higher than its level three years ago of $\$ 49.62$.
C. There is sufficient evidence to conclude that the mean monthly cell phone bill is less than its level three years ago of $\$ 49.62$.

Step 1 ：The question is about hypothesis testing in statistics. The null hypothesis, which is the initial claim, states that the mean monthly cell phone bill is not higher today than it was three years ago.

Step 2 ：The question states that this null hypothesis is not rejected. This means that there is not enough evidence to support the claim that the mean monthly cell phone bill is higher today.

Step 3 ：Therefore, the correct answer should be B. There is not sufficient evidence to conclude that the mean monthly cell phone bill is higher than its level three years ago of $49.62.

Step 4 ：Final Answer: \boxed{\text{B. There is not sufficient evidence to conclude that the mean monthly cell phone bill is higher than its level three years ago of $49.62}}.