The average human gestation time is 266 days from conception. A researcher suspects that proper nutrition plays an important role and that low-income women with inadequate food intake would have shorter gestation times even when given vitamin supplements. A random sample of 20 low-income women who were given vitamin supplement throughout their pregnancy had a gestation time from conception of x - 256 days The researcher's alternative hypothesis for the test is:______.
a. Ha : μ =/ 256.
b. Ha: μ = 266.
c. Ha : μ < 266.
d. Ha : μ < 256.