Which word describes someone who is unselfish and concerned with the welfare of others?

The word that describes someone who is unselfish and concerned with the welfare of others is "altruistic." This term specifically refers to an individual who is motivated by a genuine desire to help others, rather than by self-interest. Altruistic behavior often entails putting the needs and well-being of others before one’s own, demonstrating compassion, generosity, and a commitment to the greater good.

In contrast, the other choices refer to characteristics that lack this selflessness: "selfish" indicates a tendency to prioritize one's own needs and desires over those of others; "indifferent" suggests a lack of concern or interest in the welfare of others; and "egocentric" describes a focus on oneself that disregards others' needs and feelings. Thus, "altruistic" stands out as the term that embodies the spirit of unselfishness and concern for others.