The passage says "
[...] he does rightly see Jackson's tenure as the culmination of the acceptance of party, commerce and individualism".
Therefore, (A) "Many supporters resisted the commercialization [...]" it's clearly in contrast with the stated in the passage.
B says "
Protest against the corrupt and partisan nature of political parties in the United States subsided during Jackson's presidency", and the passage says "
non-partisanship lost its relevance, [...] party gained a new legitimacy", that is, B is supporting the passage IMO.