She left out one of faces of the solid. She should have simplified 2 times open paren 5 times 7 close paren plus 2 times open paren 6 times 7 close paren plus 2 times open paren 1 half 5 9 point 3 close paren plus 2 times open paren 1 half 6 9 point 2 close paren plus 5 times 6 .
B
She used the wrong expression for the lateral faces of the solid and left out the base of the figure. She should have simplified 2 times open paren 1 half 5 open paren 7 plus 9 point 3 close paren close paren plus 2 times open paren 1 half 6 open paren 7 plus 9 point 2 close paren close paren plus 5 times 6 .
C
She used the wrong expression for the lateral faces of the solid. She should have simplified 2 times open paren 1 half 5 open paren 7 plus 9 point 3 close paren close paren plus 2 times open paren 1 half 6 open paren 7 plus 9 point 2 close paren close paren .
D
She included the face where the pyramid and prism are joined together. She should have simplified 2 times open paren 5 times 7 close paren plus 2 times open paren 6 times 7 close paren plus 2 times open paren 1 half 5 9 point 3 close paren plus 2 times open paren 1 half 6 9 point 2 close paren minus 2 times open paren 5 times 6 close paren .