Answer:
B: Retain the null hypothesis
Explanation:
In the relationship between the confidence interval and hypothesis, it is stated that:
When the confidence interval is constructed, all values that fall inside the interval are considered possible values for the parameter that we are estimating while values that fall outside the interval are rejected as they are considered not possible or realistic values.
Now, If the value of the parameter specified by the null hypothesis falls inside the given confidence interval, then we will fail to reject the null hypothesis at the corresponding significance level. However, If the value specified by the null hypothesis doesn't fall inside the given confidence interval, then the null hypothesis can be rejected at the corresponding significance level.