Classify the hypothesis test as two-tailed, left-tailed, or right-tailed. At one school, the average amount of time that tenth-graders spend watching television each week is 20.3 hours. The principal introduces a campaign to encourage the students to watch less television. One year later, the principal wants to perform a hypothesis test to determine whether the average amount of time spent watching television per week has decreased from the previous mean of 20.3 hours.

a. Two-tailed
b. Right-tailed
c. Left-tailed