For the K map in the given figure, the simplified expression is

• A. xl x2 x4 + x2 x4 + x1 x3
• B. x2 x4 + x2 x4 + x1 x3
• C. x1 x2 x4 + xl x2 + x3 x4 + x2x4
• D. x1 x2 + x2 x3 + x3x4