单选题 All else being equal, an increase in the price of one product will most likely cause the demand curve of the product's supplement to:
A. Remain unchanged.
B. Shift upward and to the right.
C. Shift downward and to the left.

【正确答案】 C

【答案解析】[解析] 两种商品是补充关系，一种商品价格上升，会导致另一种商品的需求量下降，所以另一种商品的需求曲线会整体向左移动。