Zero group was introduced by:
A. Lother Meyer
B. Mendeleev
C. Ramsay
D. Lockyer

Hint: Zero groups is a group of a noble gas. Noble gases are said to be zero group elements because they have zero valencies and they cannot combine with other elements to form compounds. The zero group elements are Helium, Neon, Argon, Krypton, Xenon, and Radon. Zero group elements are known as:
Gases of the atmosphere: Because these gases occur in the atmosphere.
Rare gases or Aerogenes. Because they occur in the atmosphere in very small amounts.
Inert gases. Because they are chemically inert.
Noble gases. They are better called noble gases because recently many compounds of these elements have been prepared.

Complete step by step answer:
Zero group elements or the noble gases were discovered and introduced by William Ramsay in 1902. Noble gases are colourless, odourless, and tasteless gases that are very slightly soluble in water. They can be liquefied and the boiling points of the liquid gases increase in the order of their increasing atomic numbers. Zero group elements are monatomic gases.
After discussing we can conclude that Ramsay introduced the zero group elements.

Thus, the correct option for the given question is (C).

Note: The main sources of noble gases are:
Earth’s atmosphere: Except radon (formed by the radioactive decay of radium), all noble gases are present in the earth’s atmosphere. The relative amounts (in percent volume) of different noble gases present in the atmosphere are shown in the table below:



From the above table, we can say that Argon is the most abundant noble gas.
1.Natural gas: It contains mainly helium.
2.Stars and Interstellar space: The Sun's atmosphere contains large amounts of helium where it is formed from hydrogen.
3.Minerals and Spring waters: Minerals like thorianite, pitchblende, and monazite contain helium in the occluded form. Certain spring waters also contain small quantities of Helium and Argon.
4.From Disintegration of Radioactive elements: Radon is evolved by the disintegration of radioactive Radium.