The following question, consist of two words each that have a certain relationship to each other, followed by four lettered pairs of words. Select the lettered pair that has the same relationship as the original pair of words: Carbon : Diamond :: Corundum : ?

The correct answer is: Ruby.

In the original pair, “carbon” is the chemical element that forms the mineral “diamond”. Corundum is an aluminum oxide mineral that can be found in a variety of colors, including red, pink, orange, yellow, green, blue, purple, and brown. The red variety of corundum is called ruby.

Pearl, pukhraj, and garnet are all minerals, but they are not related to corundum in the same way that carbon is related to diamond. Pearl is a calcareous concretion produced within the soft tissues of a living shell-bearing mollusk. Pukhraj is a yellow variety of beryl. Garnet is a nesosilicate mineral group consisting of nesosilicates with garnet-type

crystal structure.

Therefore, the only lettered pair that has the same relationship as the original pair is “corundum : ruby”.