Identify the contracts or contractual clauses described in each of the following examples.

a. A wireless company offers to sell you a smartphone only if you also buy a bluetooth headset.

b. A car manufacturer limits the area in which a dealership can sell to 20 miles beyond the city boundary.

c. A printer company sells its printers to a customer at a very low price, with the contract specifying that the customer must purchase only its printers.

d. A state university signs a 10-year, $32 million contract with a soft drink company specifying that only the company’s products may be sold on the campus.

Which of these examples, if any, would be illegal under the Clayton Act and should therefore be avoided?