The question asks about the synthetically produced radioactive noble gas produced by the collision of Californium-249 (²⁴⁹Cf) with Calcium-48 (⁴⁸Ca).
Oganesson (Og): The collision of Californium-249 with Calcium-48 results in the creation of Oganesson (Og), a highly radioactive noble gas with atomic number 118. It is a synthetic element.
Radon (Rn): Radon is a naturally occurring noble gas and not formed in this reaction.
Radium (Ra): Radium is a radioactive element, but not a noble gas.
Xenon (Xe): Xenon is a naturally occurring noble gas, and it is not formed in this reaction either.
The correct synthetically produced noble gas is Oganesson (Og), so the correct answer is (C).