Scientist: Venus contains a hot molten core, like that of Earth. Also like Earth, Venus must expel the excess heat the core generates. On Earth, this occurs entirely through active volcanos and fissures created when tectonic plates separate. Yet Venus has neither active volcanos nor fissures caused by the movement of tectonic plates. Which one of the following, if true, does the most to resolve the apparent discrepancy described by the scientist? ['The atmosphere of Venus is significantly hotter than that of Earth.', 'Rock on the surface of Venus remains solid at much higher temperatures than does rock on Earth.', 'Though Venus lacks active volcanoes and heat- diffusing fissures, it has surface movement somewhat like that of Earth.', 'The surface of Venus is relatively thin, allowing internally produced heat to radiate into space.']