Saundra Says That Whenever She Drinks Coffee in the Evenings

Saundra says that whenever she drinks coffee in the evenings it interferes with her ability to fall asleep.The more coffee she drinks before sleeping,the less sleep she gets.In the context of correlational research,Saundra is describing a _____ between caffeine intake and sleep.

A) negative correlation
B) positive correlation
C) causal relationship
D) lack of relationship