Jayden wants to lay sod on his front yard and on half of his back yard. His front yard has a length of 50 feet and a width of 70 feet. His back yard has a length of 10 feet and a width of 40 feet. How many square feet of sod does Jayden need to purchase? A. 3,900 square feet B. 3,600 square feet C. 3,700 square feet D. 2,150 square feet