求助！情态动词是否能随意添加或删除的问题！GWDT-3-Q38.

安静的小兔

T-3-Q38.
The normative model of strategic decision-making suggests that executives examine a firm’s external environment and internal conditions, and in using the set of objective criteria they derive from these analyses, can decide on a strategy.

A.    conditions, and in using the set of objective criteria they derive from these analyses, can decide
B.    conditions, and they use the set of objective criteria derived from these analyses in deciding
C.    conditions, and, in using the set of objective criteria derived from these analyses,  deciding
D.    conditions and, using the set of objective criteria derived from these analyses, decide
E.    conditions, and in their use the set of objective criteria they derive from these analyses, decide

这道题为什么不能选B, and 前面加逗号连接连个句子， 是不是因为这样的话they 语法上应该指代executives, 但语法应该指代model 但又是单数？ 还有后面的in deciding 也有问题？？？