Final answer:
Corporate heads chose to initiate a smear campaign against William Jennings Bryan to discredit his campaign, rather than supporting him.
Step-by-step explanation:
William Jennings Bryan, known for his denunciation of corporate power and political corruption, encountered strong opposition from corporate heads and financial interests. Far from supporting Bryan, these powerful individuals and entities chose to discredit him and derail his campaign efforts. In the election of 1908, the corporate elite and other political adversaries of Bryan initiated a smear campaign to undermine his appeal to the American electorate. This approach was intended to sway public opinion against Bryan and maintain the status quo that favored business interests.
Thus, in response to what the powerful corporate heads decided to do in reaction to Bryan's anger-fueled campaign for the White House, the correct answer is option c) They initiated a smear campaign against Bryan to discredit him.