How do you know that you truly love someone?

In other words, your happiness is their happiness, and your pain is their pain. “Someone in love will care about your feelings and your well-being,” Dr. Flores said. “If he or she is able to show empathy or is upset when you are, not only do they have your back, but they also probably have strong feelings for you.”

love is a very complex thing, and means different thingd to different people. I realized i was in love when I was sitting there, head on his shoulder, in a rooom full of peopel, but no one in that room mattered more than him, and I felt so safe in his arms and like no one could hurt me

Explanation:

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 .