Sentence Correction - Expert Help

[mainhoon]

The ancient Romans piped hot water through the walls and under the floors so as to warm up the rooms.

A. so as to warm up the rooms
B. and so would be able to warm up the rooms
C. to warm the rooms up
D. so that they could warm up the rooms
E. in order that they would warm up the rooms

Why exactly is A wrong?

[paes]

try to search the question before posting :
Also underline the question properly.
Put your doubt under spoiler.

https://www.beatthegmat.com/to-or-in-ord ... 12731.html
https://www.manhattangmat.com/forums/so- ... t8142.html
https://www.beatthegmat.com/ancient-romans-t16864.html

A : is wrong. usage of 'so as' is wrong on GMAT
You can use : so X as to (be) Y

but 'so as' is incorrect.

[mainhoon]

Thanks!