The correct answer is A. Is that which benefits others while causing a disadvantage to the individual.
Explanation:
In biology, altruistic behavior occurs as one organism actions benefit other organisms either because these actions increase the reproductive fitness or the chances an organism survives and prevails over time. Additionally, altruistic behavior implies there is a disadvantage for the organisms acting in the benefit of others. For example, wolves or similar animals take food to those that did not participate in hunting, which means they help other wolves to survive on their own cost as this means less food for those that hunted. According to this, altruistic behavior "is that which benefits others while causing a disadvantage to the individual".