He is __________ to the needs of others.

The correct answer is sensitive. To be sensitive to the needs of others means to be quick to detect, understand, and respond to their feelings, requirements, or difficulties. It implies empathy, awareness, and a readiness to act thoughtfully in consideration of others. This is a common and correct idiomatic expression. Let's consider the other options: Sensible describes someone who makes good judgments, is practical, or acts with wisdom and prudence. While a sensible person might also be sensitive, the word "sensible" itself doesn't directly convey the idea of being responsive to others' needs. Senseless means lacking meaning, purpose, or common sense; foolish, which is the opposite of the intended meaning. Sentimental refers to feelings of tenderness, sadness, or nostalgia, often associated with emotional attachment to things or memories. While it relates to emotions, it doesn't accurately describe the quality of being aware of and responsive to the practical or emotional needs of other people in an empathetic way, as "sensitive" does.