Say whether each of the following situations is an example of altruism or reciprocity.
a. Giving a few canned goods to the local food bank for its annual food drive.
b. Helping someone move her couch after she helped you study for an upcoming exam.
c. The biological relationship between cleaner fish and large predators in the ocean, in which cleaner fish keep the predator free from parasites and the predator keeps the cleaner fish safe.