The correct answer is: D. Mirage
A mirage is an optical phenomenon that causes an image of distant objects to appear displaced from their true position. It is most commonly seen in hot, dry regions, such as deserts, but can also occur in other places, such as over roads on hot days.
The word “mirage” comes from the Latin word “mirare”, which means “to look at”. Mirages are caused by the refraction of light as it passes through layers of air of different densities. When the air is heated, it becomes less dense, and light travels faster through it. This causes the light to bend, and the image of the object to appear displaced.
There are two main types of mirages: inferior mirages and superior mirages. Inferior mirages are the most common type, and they occur when the air near the ground is warmer than the air above it. This causes the light to bend upwards, and the image of the object to appear to be floating above the ground. Superior mirages are less common, and they occur when the air near the ground is cooler than the air above it. This causes the light to bend downwards, and the image of the object to appear to be sinking below the ground.
Mirages can be very realistic, and they can sometimes be mistaken for real objects. However, if you look closely, you will usually be able to see that the image is not quite right. For example, the image of a tree may appear to be floating in the air, or the image of a road may appear to be wet.
Mirages are a fascinating phenomenon, and they can be a lot of fun to watch. However, it is important to remember that they are not real, and they can be dangerous if you are not careful. For example, if you are driving and you see a mirage of a lake, you may be tempted to drive into it. However, the lake is not real, and you will end up driving off the road.
In Sanskrit, a mirage is known as “deer’s thirst”. This is because deer are often seen looking at mirages, which they believe to be real lakes. The name “deer’s thirst” is a reminder that mirages are not real, and that they can be dangerous if you are not careful.