The correct answer is (a) Xenon.
Xenon is the noble gas that forms the maximum number of compounds. It has been found to form compounds with a variety of elements, including fluorine, oxygen, chlorine, and bromine. These compounds are typically very unstable and decompose at room temperature. However, they have been studied extensively by chemists because they provide insights into the bonding properties of noble gases.
Neon, helium, and argon are the other three noble gases. They are all very stable and do not form compounds under normal conditions. However, neon has been found to form a few compounds with fluorine at very low temperatures. Helium and argon have not been found to form any compounds.
The reason why xenon forms more compounds than the other noble gases is because it has a larger atomic radius. This means that its electrons are further away from the nucleus, and they are therefore less strongly attracted to it. This makes it easier for xenon to form bonds with other atoms.
The compounds that xenon forms are typically very reactive. They are often used in lasers and other applications where a high-energy reaction is desired.