Charlotte is studying subliminal messages and weight loss. She is curious whether people will lose more weight if they hear subliminal messages that encourage weight loss ("don't eat that food," "you want to be thin") in the music on their iPods compared to people who do not have subliminal messages in their music. She studies 40 people and finds the following results:

To understand whether the subliminal messages have an effect, Charlotte needs to consider all of the following cells:

Cell A
She must consider all the cells
Cell B
Cell C