Question

tone means :
a force that compels
the quality that renders something desirable
a quality of a given color that differs from another color
dignified manner or conduct

Explanation:

In language - related contexts, "tone" can refer to a dignified manner or conduct. It is not a force that compels (that is more related to concepts like coercion), not the quality that makes something desirable (which is more like value or appeal), and not a quality of color difference (which is more about hue or shade).

Answer:

dignified manner or conduct