Answer:
The correct answer is option A. "a fossilized fish found in a layer of rock estimated to be between 15,000 and 25,000 years old".
Step-by-step explanation:
It is estimated that the oldest fossils that can be reliably measured using carbon-14 must be organic and have an age of around 50,000 years. Therefore, a fossilized fish found in a layer of rock estimated to be between 15,000 and 25,000 years old will fit perfectly to be dated using carbon-14. Anything older than 50,000 years old must be dated using other radiometric dating approaches.