A researcher for a store chain wants to test the assumption that the mean proportion of all people who stop in the store(s) who try the samples offered is 0.15. She thinks that the proportion is actually higher than 0.15. The null and alternative hypotheses for this test are ________.
a. Null hypothesis: The mean proportion of all people who stop in the store(s) who try the samples offered is 0.15. Alternative hypothesis: The mean proportion of all people who stop in the store(s) who try the samples offered is greater than 0.15.

b. Null hypothesis: The mean proportion of all people who stop in the store(s) who try the samples offered is greater than 0.15. Alternative hypothesis: The mean proportion of all people who stop in the store(s) who try the samples offered is 0.15.

c. Null hypothesis: The mean proportion of all people who stop in the store(s) who try the samples offered is equal to 0.15. Alternative hypothesis: The mean proportion of all people who stop in the store(s) who try the samples offered is not equal to 0.15.

d. Null hypothesis: The mean proportion of all people who stop in the store(s) who try the samples offered is less than 0.15. Alternative hypothesis: The mean proportion of all people who stop in the store(s) who try the samples offered is equal to 0.15.