Consider the following statements in case of terrestrial planets: I. Mercury, Venus, Earth and Mars are terrestrial planets having low densities as compared to other planets. II. They lie between the Sun and the belt of asteroids. III. Their lower gravity can hold the escaping gases. Which of the statements given above is/are correct?

Only statement II is correct. The terrestrial planets — Mercury, Venus, Earth and Mars — are located between the Sun and the asteroid belt. Statement I is incorrect because terrestrial planets actually have HIGHER densities (rocky composition) compared to the gas giants (Jovian planets) which have lower densities. Statement III is incorrect because the lower gravity of terrestrial planets cannot hold lighter escaping gases like hydrogen and helium, which is why they have thinner atmospheres compared to Jovian planets.