During the maturity stage of the product life cycle, profit declines primarily because: multiple choice a) there is fierce price competition among sellers. b) more consumers enter the market seeking bargains. c) promotional expenditures increase. d) production costs increase the more a firm has to manufacture the same product. e) there are fewer and fewer competitors in the market.

Plastic and steel are substitutes in the production of body panels for certain automobiles. if the price of plastic increases, with other things remaining the same, we would expect: a) the demand curve for plastic to shift to the left. b) the price of steel to fall. c) the demand curve for steel to shift to the left d) nothing to happen to steel because it is only a substitute for plastic. e) the demand curve for steel to shift to the right