Vanessa Claims That She Sleeps Better When She Falls Asleep

Multiple Choice

Vanessa claims that she sleeps better when she falls asleep to music.She has a comparison group,because she has noticed that she does not listen to music every night,only when she remembers to plug in her iPod.She typically remembers to plug in her iPod on nights when she is able to finish studying earlier.What problem do you see in Vanessa's reasoning about sleeping better to music?

A) Vanessa may be sleeping better because she is less distracted by studying/going to bed sooner.
B) Vanessa's belief that she sleeps better with music is not falsifiable.
C) Vanessa is biased because she sleeps in the same bed every night.
D) There is no problem with Vanessa's reasoning.