I can assure you we've spared no effort and spent quite a sum of money in pushing the sales of your products.

I can assure you we've spared no effort and spent quite a sum of money in pushing the sales of your products.

A.我方保证为了推销你方产品，我们尽心尽力，并且花费了一大笔资金。

B.我可以向你保证在推销你方的产品时，我们已经尽力，并且花了巨资。

C.我方保证，我们不遗余力地推销你方产品，花了不少钱。

D.我可以向你保证在推销你方的产品时，我们从没放松努力，并且动用了大量的资金。

正确答案是D