The correct answer is "B": There is now no restriction on the amount of money that organizations or individuals can give to candidates in national elections due to a ruling by the Supreme Court.
The day after the 2002 midterm elections, new federal laws concerning campaign finance which became known as the Bipartisan Campaign Reform Act (BCRA), were put into effect. The BCRA increased the contribution limits for individuals who wanted to give money to federal candidates and political parties. The Federal Election Commission updated these contribution limits every two years since these limitis had to be indexed to inflation. However, since 2014, according to a Supreme Court's decision, there is no longer a limit on how much an individual can give in total to all candidates and party committees.