Use the Following to Answer Questions

Multiple Choice

Use the following to answer questions :
A researcher wants to test if the elementary school children spend less than 30 minutes per day on homework.A random sample of 64 children from the school shows that they spend an average of 24.5 minutes per day on homework.Assume that 15.3 minutes,and that the test is to be made at the 1% significance level.
-What is the critical value of z?

A) -2.06
B) -2.33
C) -2.58
D) -1.96