The correct answer is A. old. A fossil is the remains or impression of a prehistoric plant or animal embedded in rock. Fossils are formed when the remains or traces of an organism are buried in sediment and subjected to heat and pressure over millions of years. The process of fossilization is a very slow one, and it is only the most durable remains that are likely to be preserved. As a result, fossils provide us with a unique glimpse into the past, and they can tell us a great deal about the history of life on Earth.
The other options are incorrect. Option B, fake, is incorrect because the geologists declared that the fossil was authentic. Option C, new, is incorrect because fossils are formed over millions of years, and therefore they are not new. Option D, beautiful, is incorrect because the question is asking about the authenticity of the fossil, not its beauty.