Answer:
b.) Two-tailed test
Explanation:
Blake hypothesizes that the average age of the population of Texas is not equal to 38 years.
This means that at the alternative hypothesis, we test if the average is different of 38, that is:
![H_1: \mu \\eq 38](https://img.qammunity.org/2022/formulas/mathematics/college/1l4hwti34ct37nl4a84dhzv8s6wd084lv7.png)
When the test at the alternative hypothesis is of difference, we have a two-tailed test, and thus the answer is given by option b.