Which of the following correctly shows the re-grouping strategy for solving 57 x 18?
50 x 10; 7 x 10; 10 x 8; 7 x 8
50 x 10; 7 x 10; 50 x 8; 7 x 8
50 x 10; 7 x 50; 50 x 8; 7 x 8
10 x 8; 7 x 10; 50 x 8; 7 x 8