A certain medical health association reports that the average cost of a 6-month medication for a patient with tuberculosis is ₱26 500. To see if the average cost is different in a nearby hospital, a researcher randomly sampled 25 patients from the said hospital with tuberculosis and found that the average cost of their medication is ₱24 800 with a standard deviation of ₱1 300. Calculate the test statistic for the hypothesis testing.
A. 6.3
B. 6.5
C. 6.7
D. 6.9