Final answer:
Friendliness with a purpose is best described as social skill, which involves the ability to interact effectively with others in a social context and is related to prosocial behavior and empathy.
Step-by-step explanation:
Friendliness with a purpose describes social skill, which is the ability to interact effectively with others in a social context. This concept is often related to emotional intelligence and prosocial behavior. Prosocial behavior is a voluntary behavior with the intent to help other people. It includes different elements like empathy, which is the capacity to understand another person's perspective and feelings, and can be linked to acting altruistically towards others.
Empathy can motivate altruism, leading individuals to engage in prosocial behavior without expectation of reciprocity or reward. Conversely, acting in a friendly manner with the sole aim of winning favor or influencing someone, without genuine care or empathy, could be considered obsequiousness. Hence, the best match for 'friendliness with a purpose' is indicative of a social skill that involves genuine interest in the wellbeing of others, facilitating cooperative and positive interactions.
The option that best fits the description of 'friendliness with a purpose' is thus D) Social skill.