Final answer:
The presence of other bystanders (B) does not increase the likelihood of a bystander's intervention and, in fact, can lead to diffusion of responsibility, thereby decreasing the likelihood of help being offered.
Step-by-step explanation:
The likelihood of bystanders helping:
The factor that does not increase the likelihood of bystanders helping is B. Presence of other bystanders in the situation. According to the principle of the bystander effect and diffusion of responsibility, when there are more bystanders present during an emergency or violation of social norms, individuals tend to feel less compelled to intervene. This phenomenon suggests that as the number of witnesses increases, each person feels less personal responsibility to act, under the assumption that someone else will respond.
Conversely, factors that do increase the likelihood of bystander intervention include A. Feeling good, successful, happy, or having a positive mood; as well as C. Knowing what to do or how to help in the situation, which provides the bystander with confidence to take action. Additionally, D. Perceiving the other person as deserving of help can also influence one's decision to offer assistance as it relates directly to the motivation behind the prosocial behavior. These elements can significantly raise the chances that a bystander will actively provide help.