For which of the following is there no such thing as a "price?"

What three things must a firm know in order to calculate costs?

What will be an ideal response?

In the above figure, the demand curve for Good A shifts from D1 to D2 in Graph A when the price of Good B changes from P1 to P2 in Graph B. We can conclude that

A) Good A and Good B are substitutes. B) Good A and Good B are complements. C) Good A is a normal good but Good B is an inferior good. D) Good A and Good B are unrelated.