Carbon-14 dating would be useful in finding the age of

A.

a fossilized fish found in a layer of rock estimated to be between 15,000 and 25,000 years old.

B.

a fossilized spore estimated to be over 200,000 years old.

C.

a sedimentary rock with a leaf imprint of undetermined age.

D.

an index fossil known to have lived in the oceans 1 million years ago.

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".

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.