1. The answer is: B. Macrophage processes foreign antigen for presentation to T helper cells which activate B cells to produce antibodies. 3. The answer is: MHC class II markers MHC class II markers are needed for T helper cell binding to other immune cells. Solution 1. The answer is: B. Macrophage processes foreign antigen for presentation to T helper cells which activate B cells to produce antibodies. 3. The answer is: MHC class II markers MHC class II markers are needed for T helper cell binding to other immune cells..