Which of the following best describes discrimination?

Discrimination is best described as unjustifiable negative behavior toward a group and its members. This characterization highlights that discrimination involves biased actions that are not based on valid or fair grounds, leading to unfair treatment of individuals based on their group membership. Such behaviors can manifest in various forms, including social exclusion, prejudice, and hostility, and they can be directed towards various characteristics, such as race, gender, sexual orientation, or ethnicity.

In contrast to discrimination, justifiable positive behavior toward a group focuses on favoritism or biased preferences, which does not capture the essence of unjust treatment. Cultural acceptance of diversity involves valuing and respecting differences among groups, which is contrary to the negative implications of discrimination. Lastly, neutral behavior towards people from other groups does not embody the active negative actions that characterize discrimination, as it suggests a lack of bias rather than a negative stance.

Thus, the definition pinpointed in the correct choice encapsulates the negative and unjust nature of actions that constitute discrimination across various contexts, making it the most accurate description.