Question

There seems to be a correlation between the price of milk and dinner rolls. In other words, when the price of milk goes up, the price of dinner rolls goes up, and when the price of milk goes down, the price of dinner rolls goes down.

Which fact would lead you to believe that the relationship between the prices is not only a correlation, but also one of causation?
is it D or B?
D)
The prices of milk and dinner rolls both move with the rate of inflation.
B)
Milk and dinner rolls are often served during the same meal.