Comets are made mostly of ice and dust. As comets get close to the sun, they start to “melt” and release what?

Question

Accepted Answer

Steam, gas and dust. C is correct because comets release ice (which becomes steam), gas from sublimation, and dust. A is incorrect because it misses the gaseous components released by heating. B is incorrect because it omits the component of steam which comes from melting ice. D is incorrect because comets do release material when near the sun.