The correct option is C is opaque to infrared rays
The Greenhouse Effect is the process where infrared radiation from the Sun is absorbed by gases in the atmosphere, thus helping to heat the Earth.
Gases like oxygen and nitrogen are transparent to incoming sunlight, they are also transparent to outgoing thermal infrared. However, water vapor, carbon dioxide, methane, and other trace gases are opaque to many wavelengths of thermal infrared energy. Greenhouse gas molecules absorb thermal infrared energy and their temperature rises.