Please help me to solve following managerial accounting questions. Thank you so much.

Your company is choosing the price to change for one of its products. The product provides a foot in the door for your business. (Choosing from options list for each situation: Demand substitutability; Supply complementarity; Higher; Demand complementarity; Lower; Equal; Supply substitutability) a) All else equal, the fact that the product provides a foot in the door, means the optimal price should bi? b) What term do we use to refer to this type pf product interaction? Briey explain why a budget must be used as an evaluation tool in order for it to be effective as a control device