Let A = {x, y, z}, B = {v, w, x}. Which of the following statements is correct?

• A. A U B ={v, w,x, y, z}
• B. A U B = {v, w,y, z}
• C. A U B = {v,w, x, y}
• D. A U B ={x,w, x, y, z}