The center of the asteroid belt is approximately 404 million kilometers from the sun. state the name of the
planet that is closest to the center of the asteroid belt.

The Asteroid Belt is located between the orbits of Mars and Jupiter: so it can only be one of the two planets that is the closest to it.

Mars is located approx 250 million km from the Sun and Jupiter - 750 million km from the Sun.

Mars is closer: so the correct answer is: Mars is the planet closest to the Asteroid belt.