Political machines were likely to approve public work projects for companies that

a)were qualified.

b)were anti-union.

c)promised their votes.

d)promised good discounts.

Political machines were likely to approve public work projects for companies that  promised their votes.  Option C is correct.

A political machine constitutes a political group or party organization in which an authoritative boss or small group orders the support of a corps of supporters and businesses who tend to be campaign workers, and they receive rewards for their effort.

answer; i believe that the correct answer is (tabula rasa);