please help with this four step math problem. I realize that it is a lot and I apologize, but you wouldn't be able to answer the fourth question without the first question. thank you.

The political pollster Canter is preparing for a national election. It would like to poll at least 1,500 Democrats and 1,500 Republicans. Each mailing to the East Coast gets responses from 100 Democrats and 50 Republicans. Each mailing to the Midwest gets responses from 100 Democrats and 100 Republicans, and each mailing to the West Coast gets responses from 50 Democrats and 100 Republicans. Mailings to the East Coast cost $40 each to produce and mail, mailings to the Midwest cost $60 each, and mailings to the West Coast cost $50 each. How many mailings should Canter send to each area of the country to get the responses it needs at the least possible cost? What will it cost? Define variables for the problem according to the goal, i.e. x: number of mailings to the East Coast y: number of mailings to the Midwest z= number of mailings to the West Coast Which of the following best describes the objective of this problem? Select one: A a. The objective function is 100x + \"My + 50z. and we are trying to minimize the number of responses from Democrats. C b. The objective function is 1500): + 1500y, and we are trying to maximize the number of people polled. A c. The objective function is 50x + 100); + 100z, and we are trying to minimize the number of responses from Republicans. \"W d. The objective function is 150x + 200y + 150z, and we are trying to minimize the number of responses from both parties. A e. The objective function is x + y + z, and we are trying to minimize the number of mailings sent out. \"W f. The objective function is 40x + 6032 + 50z, and we are trying to minimize cost. Select all of the constraints associated with this problem from the list below. Select one or more: O a. 50x + 100y + 100z 1500 0 9. z 3000 Oi. x20 Ojyso OK. x5 0Convert the problem into a maximization problem, and introduce surplus variables to obtain the initial tableau. You should arrive at the following: 5* 1500 t* 1500 p 0 What is the next pivot element in the simplex algorithm? Select one: CI 8. The 1,2entry. C b. The 2,3entry. C c. The 2,1entry. C d. The 3,1entry. C e. The 2,2-entry. C f. The 1,1-entry. Which of the following yields the minimal cost when plugged into the cost equation? Select one: O a. (0, 0, 15) O b. (0, 15, 0) O c. (10, 0, 10) O d. (15, 0, 0) What is the minimal cost attained by the optimal solution?