The Level of Calcium in the Blood of Healthy Young

Multiple Choice

The level of calcium in the blood of healthy young adults follows a Normal distribution, with mean μ= 10 milligrams per deciliter and standard deviation σ= 0.4. A clinic measures the blood calcium of 25 healthy pregnant young women at their first visit for prenatal care. The mean of these 25 measurements is x̄= 9.6. Is this evidence that the mean calcium level in the population from which these women come is less than 10? To answer this, test the following hypotheses:
H₀: μ= 10 versus H_a: μ< 10
If the P-value of your test is less than 0.0002, what would you conclude?

A) H₀ should be rejected.
B) H₀ should not be rejected.
C) H_a should be rejected.
D) There is a 5% chance that the null hypothesis is true.