OPTIONS:
(I) space.
(II) living things.
(III) hydrogen and oxygen.
(IV) massless objects.
(V) objects that have mass.
(VI) fissures of hot, acidic water.
(VII) nothingness.
(VIII) principals of aerodynamics.
Q: Fact 1: Gravity causes objects that have mass to be pulled down on a planet. Fact 2: Another name for Mars is the Red Planet. Given the two facts above, gravity causes what to be pulled down on Mars?
A:
(V)