A researcher selected a random sample of airline pilots. Each pilot was tested on a signal detection task after 24 hours of sleep deprivation and tested again on the signal detection task after 48 hours of sleep deprivation. What statistical test would be used to determine if amount of sleep deprivation has a significant effect on signal detection performance? Select one: a 2-test Ob dependent-samples t-test Oc one-sample t-test Od independent-samples t-test