A researcher is interested comparing quality of sleep between people who work overnight shifts and people who work day shifts. A sample of 50 day shift workers and 50 night shift workers are asked to complete a quality of sleep measure, which the researcher will treat as an interval scale measure. The researcher will compare the mean levels of each group to see if there is a statistically significant difference between the groups. Which analysis would be acceptable to use?

a. one-sample t-test
b. Independent samples t-test
c. Pearson's r
d. Paired-samples t-test