Answer: b) By redirecting the URLs, those URLs will no longer rank independently on search engines, moving other (potentially negative) sites up higher in the rankings
Explanation:
The Non-profit Organization is shooting itself in the foot by purchasing the more positive sites and then setting them up in such a way that they will be redirected to their home page.
This is because when sites merely redirect, they lose their independence ranking. As this happens their place will be taken on search engines.
Seeing as the Nonprofit did this more with positive sites, there is a high chance that the sites that will replace those positive sites will be negative sites meaning that when people search for the Organization, they might see more negative information.