The average life of light bulbs produced by SABA Electric Co. is expected to be normally distributed with the mean service life of 950 hours and standard deviation of 100 hours. A consumer agency tests a random sample of 100 bulbs and finds mean service life of 910 hours. If the agency conducts hypothesis testing, which set of ideas can she formulate for her research? H0 is null hypothesis, and Ha is alternative hypothesis.

• A.H0: = 950 and Ha: is not equal to 950
• B.H0: = 950 and Ha: <950
• C.H0: = 910 and Ha: <910
• D.H0: = 910 and Ha: > 910