Which of the following conditions are necessary for marketing to occur? a. two or more people, a method of assessing needs, a way to communicate, and an exchange b. two or more people, a product, a reasonable price, and a place to make an exchange c. a quality product, a fair price, a clever method of promotion, and a place where a customer can buy the product d. two or more parties with unsatisfied needs, a desire and an ability to satisfy them, a way to communicate, and something to exchange e. an ability to see a hidden trend within an environmental force, a product, and an affordable and actionable advertising campaign