"Bias" means someone shows inclination towards someone or something because of the relationship that person has with that thing or person.
In this case, since Janine has friends that are also in the dance club, they are more likely to vote for her as president because they are friends with her. So, answer A is likely to be biased because the five people sampled are her friends.
Answer C is also biased because the sample chosen already plan on voting for her as president, and they are more than likely to find others who plan to vote for her.
