一道SAT语法题With the Louisiana Purchase,the United States acquir

一道SAT语法题
With the Louisiana Purchase,the United States acquired a 【larger territory in area than if you combined Britain,France,Italy,Germany,Spain,and Portugal.】
括号中如何修改?
A:保持原样
B:larger territory in area than combining Britain,France,Italy,Germany,Spain,and Portugal.
C:territory larger in area than if Britain,France,Italy,Germany,Spain,and Portugal were combined.
D:territory larger in area than Britain,France,Italy,Germany,Spain,and Portugal combined.
E:territory larger than if the area of Britain,France,Italy,Germany,Spain,and Portugal combined.