A Researcher Distributes a Survey to College Students

Multiple Choice

A researcher distributes a survey to college students.One question asks,"How many hours per night do you sleep?" and another asks,"What is your GPA?" If the study has a cross-sectional design,which conclusion is possible?

A) Students who sleep more have higher GPAs.
B) Excessive sleep boosts GPAs.
C) Because they don't sleep enough,some students have lower GPAs.
D) Having a higher GPA causes students to sleep less.