What was the name of the law that created rules governing ways interest groups could contribute to federal campaigns and allowed for the first time the creation of Political Action Committees?

The correct answer is B. The Federal Election Campaign Act (FECA).

The Federal Election Campaign Act, enacted in 1971, was the first law that established rules for the regulation of campaign contributions and expenditures in federal elections. It allowed for the formation of Political Action Committees (PACs), which are organizations that raise and spend money to elect candidates or promote political causes. This act aimed to increase transparency in campaign financing and reduce the influence of money on politics.