Annabelle works in a deli and has been tracking the daily sales of different items over several months. Annabelle found that when there was an increase in the number of cups of hot chocolate sold, the number of cups of coffee sold also increased. Similarly, when there was a decrease in the number of cups of hot chocolate sold, the number of cups of coffee also decreased. Which of the following is a valid conclusion?

A. No conclusion can be drawn about the correlation or causation of the sale of hot chocolate and the sale of coffee.
B. There is no correlation between the sale of hot chocolate and the sale of coffee.
C. The increase in the sale of hot chocolate caused an increase in the sale of coffee.
D. The increase in the sale of hot chocolate is correlated to, but not caused by, the sale of coffee.