In most corporations the salaries of executives are set by a group from the corporation's board of directors.
Background
In most corporations, the executives salaries are set by a board of directors.
The board's primary mission is the economic health of the company, not making the executives rich, so the expectation is the board will not give the executives excessively large salaries.
Conclusion
But this is poor reasoning (i.e. having the board choose the salaries should not be expected to prevent excessively large salaries).
Evidence
Most board members are executives for some other corporation, and so they have an incentive to set a really high salary for this corporation's executives.
Evaluate
This is a really weird question stem, because it's not asking us to find the flaw with THIS argument. Instead, it's saying take the rebuttal the author gives in those last two sentences and pick and answer choice where a similar rebuttal would work.
So we could call it Parallel Flaw, but the flawed argument we're trying to parallel is the first two sentences (everything leading up to the "But").
People thought it was smart to make board of directors choose CEO salaries, since the board's priorities are the health of the company, not lining the pockets of the CEO.
But ... this plan kinda backfires in a "you scratch my back, I'll scratch yours" kind of way. Since tons of these board members are CEO's at other companies, they are incentivized to make CEO pay really high so that when the board of directors at their company is deciding on their salary, they'll look around the marketplace and see really high salaries being paid to CEO's everywhere.
It's kind of like price collusion. If all the gas stations decide to raise their gas 50 cents / gallon at the same time, then they can all benefit from the higher rates.
Goal
Look for an argument where a certain judge was supposed to be unbiased, but because that judge has other things going on, there's actually a weird incentive for the judge to be biased in a certain way.