Verbal | Re: When to use 'to be'

here is one such example. the correct choice is option 'C'. I want to understand how the role of 'to be' here. Also, what is the correct usage of 'to be'.

Despite recent increases in sales and cash flow that have propelled automobile companies’ common stocks to new highs, several industry analysts expect automakers, in order to conserve cash, to set dividends more conservatively than they were.

(A) to set dividends more conservatively
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