Which of the following is an example of crowdsourcing?

a.
All of these are good examples of crowdsourcing

b.
A group of students each study a set of data and write individual papers on their findings.

c.
A group of people submit restaurant reviews to an online site that helps people find the best eating places.

d.
A group of people band together to raise money for a charity project.

c. A group of people submit restaurant reviews to an online site that helps people find the best eating places.