Ford, GM, and Stellantis produce electric vehicles. Provide an explanation for whether each of the following activities would be legal or illegal based on US antitrust law. (a) Ford, GM, and Stellantis agree not to lower prices for the rest of 2022. (b) Ford, GM, and Stellantis have electric vehicle factories in different US states, but they sell their vehicles in every US state. (c) Due to higher input prices (i.e., labor costs and computer chips), Ford, GM, and Stellantis each increased the price of new electric vehicles this year. (d) Ford, GM, and Stellantis agree to isolate dealerships into separate geographic regions of the US. Ford will take the Eastern region, GM will take the Midwest region, and Stellantis will take the Western region