A 12.27 g sample of an hydrocarbon is fully combusted. An analysis of the products yields 2.06 g of H, O and 7.47 g of nitrogen.
What is the empirical formula of the hydrocarbon?

It shows that the experiment is designed properly.

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.