The study of reality in the broadest sense, an inquiry into the elemental nature of the universe and the things in it, is known as

Metaphysics

Explanation:

Metaphysics in terms of philosophical field is defined as the concept that deals with the existence of components and environment. The world in which element is existing is the surrounding and the cause, time,space,identity etc is  studied to known about the fundamental realistic nature.

Relationship ,co-existence, attribute, connection etc is depicted from metaphysics.It is believed that natural reality is the base of this field over the material reality.

did mary wollstonecraft believe was a natural ingredient for women’s happiness?

so you should go with

a. strong