The radioactive isotope carbon-14 can be used for A) determining medical disorders
B) controlling speeds of neutrons
C) controlling fission reactions
D) determining the age of a sample

determines the age of sample Carbon-14 is used in radiocarbon dating and radiolabeling. Medically important, a radioactive isotope is carbon-14, which is used in a breath test to determine the ulcer-causing bacteria Heliobacter pylori

The radiocarbon age of a certain sample of unknown age can be determined by measuring its carbon 14 content and comparing the result to the carbon-14 activity in modern and background samples.

There is no reason to think the results are biased or not conducted properly but you should not assume the results are correct just because they were done in a laboratory so the answer would be c. it is likely to be reliable because the results support the conclusion presented.