You will be given a definition of a task first, then some input of the task.
In this task, You are given an open-domain question that can be answered based on factual information. Your task is to provide \*short\* answer (in a few words only) for the given question. The short answer can be one or more entities or it can also be boolean \*yes\* or \*no\*.

along the hpa-axis what is what factor is the first to be released in response to stress
Output:
cortisol