The correct answer is: D. Uranium – lead method.
The uranium-lead dating method is a radiometric dating method used to date geological materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were formed. The method compares the abundance of a naturally occurring radioactive isotope within the material to the abundance of its decay products, which form at a known constant rate of decay. The use of radiometric dating was first published in 1907 by Bertram Boltwood and is now the principal source of information about the absolute age of rocks and other geological features, including the age of fossilized life forms or the age of the Earth itself, and can also be used to date a wide range of natural and man-made materials.
The uranium-lead dating method is based on the decay of uranium-238 to lead-206 and uranium-235 to lead-207. The half-lives of these isotopes are 4.47 billion years and 704 million years, respectively. This means that for every gram of uranium-238, there will be 0.007 grams of lead-206 after 4.47 billion years, and for every gram of uranium-235, there will be 0.00012 grams of lead-207 after 704 million years.
The uranium-lead dating method is the most accurate radiometric dating method, and can be used to date materials that are up to 4.5 billion years old. It is the most commonly used method for dating igneous rocks, and is also used to date metamorphic rocks and meteorites.
The other methods mentioned in the question are also radiometric dating methods, but they are not as accurate as the uranium-lead dating method. The Ra-Si method is used to date rocks that are less than 1 million years old, the K-Ar method is used to date rocks that are less than 100 million years old, and the C14 method is used to date organic materials that are less than 50,000 years old.