The correct answer is (c), Uranium Dating.
Uranium dating is a radiometric dating technique that uses the decay of uranium-238 to lead-206 to date a wide range of natural and man-made materials. The technique compares the abundance of U-238 to the abundance of its decay products, such as lead-206, in a sample of unknown age. The ratio of U-238 to lead-206 in a sample is then used to calculate the age of the sample.
Uranium dating is a very accurate technique, and it has been used to date rocks and fossils that are billions of years old. The technique is also used to date artifacts made by humans, such as pottery and coins.
(a) Atomic clocks are devices that use the frequency of atomic vibrations to measure time. They are the most accurate timekeeping devices known, and they are used to set the standard for timekeeping around the world. Atomic clocks are not used to date the Earth because they are not accurate enough to measure the age of the Earth.
(b) Carbon dating is a radiometric dating technique that uses the decay of carbon-14 to nitrogen-14 to date organic materials. The technique is only accurate for dating materials that are less than 60,000 years old. The Earth is billions of years old, so carbon dating cannot be used to date the Earth.
(d) Bio clocks are biological clocks that are used to measure the age of an organism. Bio clocks are not accurate enough to measure the age of the Earth.