First check the speech of the sentence, it is in indirect speech. Authors is stating what Cynics claim.
Charge is in present tense, thus we can restate what Cynics say in the same tense.. no need to use past perfect.
Second split is fever vs less. Seats are countable thus we must use fewer. Eliminate B,D and E.
Between A and C. I rejected C because of reason explained above. It is using past perfect, but in original sentence no such tense sequence is presented.
Cynics charge that Major League Baseball
lobbied for stadiums with fewer seats to reduce supply and increase ticket prices. A. lobbied for stadiums with fewer seats to reduce supply and increase ticket prices.
B. lobbied for stadiums with less seats to reduce supply and increase ticket prices.
C. lobbied for stadiums that had fewer seats to reduce supply and increase ticket prices.
D. lobbied for stadiums that had less seats to reduce supply and increase ticket prices.
E. lobbied for stadiums that had less seats as a means of reducing supply so they could increase ticket prices.