To identify which layer of the sun they are studying based on temperature data, the astronomers can use the following information:
The highest temperatures are from the corona.
This statement is correct, as the corona is known to be significantly hotter than the other layers of the sun, even though it is further away from the core. In contrast, the core has the highest temperature, but the radiative zone and convective zone are not as hot as the corona. By comparing their temperature data to these known characteristics, the scientists can identify which layer they are studying.