Which of the following best describes the relationship between getting enough sleep and susceptibility to colds?

Getting at least 7-8 hours of sleep per night is associated with a lower risk of developing a cold after viral exposure compared with habitual short sleep.

Sleep duration has no measurable effect on susceptibility to the common cold.

Getting more sleep increases susceptibility to colds because it reduces immune vigilance.

Only people with chronic medical conditions show changes in cold susceptibility related to sleep; healthy adults are unaffected.