Nina has the flu and a high fever. her immune system is exhibiting the; 2nd 1st or 3rd line of defense. this defense is part of adaptive, innate or acquired immunity.

Nina is showing the second line of defense. This line is part of the acquired immunity.

Explanation:

The acquired immunity is part of the organism's second line of defense and is established with the organism's contact with foreign molecules that can cause harm such as viruses, bacteria, among others. The acquired immunity has the function of removing the invader that is already exposed to the cells of the organism, guaranteeing an immediate response to its attack.

When a virus, type a that causes the flu, attacks the organism's cell, the acquired immunity recognizes that virus and works to neutralize the infection and expel the foreign organism. As a result, the infected individual may experience symptoms such as coughing, sneezing and fever, until his acquired immunity is able to expel the virus.

since you have not provided the options here i   am going to give you general overview about hormone.hormone are actually the part of endocrine system in our body and produced by the endocrine glands. the hormones act like a chemical messenger   within human body. once produce by the glands they   travel through the blood stream and reach at specific or target tissue and organs   which result in control of our body function. the hormones are specific in their work and work on only the targeted tissue or organ   . with the of hormone endocrine system regulate the heart rate , metabolism, our mood and   growth as well as the development and even the sleeping cycle etc. they actually are the messenger for body cell and organs .