Without making it complicated, look for parallelism.
Consider the highlighted part,
Analyzing campaign expenditures, the media has had as a focus the high costs and low
ethics of campaign finance,but they have generally overlooked the cost of actually
administering elections, which includes facilities, transport, printing, staffing, and
technology.
This clearly suggests that to maintain the parallelism, we need"verb-ed" form, which is there only for option (c).
Ans : C
...
Consider the highlighted part,
Analyzing campaign expenditures, the media has had as a focus the high costs and low
ethics of campaign finance,but they have generally overlooked the cost of actually
administering elections, which includes facilities, transport, printing, staffing, and
technology.
This clearly suggests that to maintain the parallelism, we need"verb-ed" form, which is there only for option (c).
Ans : C
...
