Dr. Wood is interested in maternal weight gain and its relationship to infant outcome. After obtaining IRB approval, she collects a convenience sample of pregnant women who have delivered in the past year and, using their prenatal records, records their total weight gain. She then looks at their delivery room medical record and records the infant 5-minute APGAR score. The hypothesis is, "As maternal weight gain increases, newborn APGAR at birth will increase." This is an example of a ________ hypothesis. Group of answer choices indirect direct null