The answer is going to be D
Wikipedia is a website in which people can collaborate on providing information of certain topics. Anyone can edit the information, and others can peer review it. Thinkcycle is a platform that allows engineers, designers, etc. to collaborate on design projects. These sites allow people to cooperate with one another to create an informed report and to create elaborate projects. Overall, both websites are able to bring together people to cooperate to create the best report/project that they can.
I hope this is what you're asking for.
