新prep语法185！请指教！
185.(27714-!-item-!-188;#058&002536)
Because the budget package in Congress promises a combination of higher taxes and reduced spending that may slow economic growth, many in the credit markets wonder whether the Federal Reserve will compensate and help the economy by keeping interest rates low, or perhaps even if they push them lower.
A. by keeping interest rates low, or perhaps even if they push
B. by its keeping interest rates low, or perhaps even by their pushing
C. by keeping interest rates low, or perhaps even by pushing
D. through their keeping interest rates low, or perhaps even push
E. through their keeping interest rates low, or perhaps it will even push
