The correct answer is A. Characteristic of or belonging to reality as perceived, rather than as independent of mind
In language, it is common words have multiple meaning but each of them is used in different contexts. This is the case of the word subjective that means related to perception, but can also mean without a substance or use to describe a grammatical element. In the case of "discovering a theme" which refers to determine the underlying idea of a text, the definition or meaning of subjective that applies to this is "characteristic of or belonging to reality as perceived, rather than as independent of mind", because determine or discovering the theme is a process that depends on the perception of reality of individual which means is not objective or independent of mind but depends on each person.
In my personal experience In order to stay fit I do ballet and tennis. Those two things have helped me stay healthy and fit as well as creating hobbies! I also want to mention that I take vitamin supplements just in case if I am not for filling my normal vitamin intake from foods. So for example I take some vitamin C powder! I think it’s extremely important to work on your health and your physical activity because later in life all these things will affect you in a positive way so you won’t have to worry too much of your health considering the fact that you have been working on your health for the past years. I’ve also read that eating healthy can help you age backwards so you’ll look much younger at the age of 50 then you would if you didn’t take care of yourself physically. <3 have a great day