The correct option is C.
Greenhouse effect refers to the natural process which warms up the earth's surface. When the sunlight energy is incident on the earth some of it is absorbed while the rest is reflected back. The absorbed energy warms up the atmosphere and the earth surface resulting in global warming.
A similar thing will be experienced with a parked car that have its window closed in the sunlight. The glass of the window will absorb some of the light energy from the sun while the rest will be reflected back. The light that is absorbed will be converted to heat energy which will heat up the inside of the car, thus raising the temperature inside the car.
