'Fundamental' most nearly indicates which of the following?

The term 'fundamental' refers to something that is essential, foundational, or basic in nature. It describes the core principles or concepts that form the basis of a subject or system. When we refer to something as fundamental, we are highlighting its importance as a starting point or the underlying support for more complex ideas or structures.

In this context, 'basic' is the most appropriate synonym because it conveys the idea of something that is simple and essential, serving as the groundwork for further learning or understanding. This connection solidifies why 'basic' aligns closely with the meaning of 'fundamental.'

Other terms like 'complex,' 'additional,' and 'advanced' do not accurately reflect the simplicity or foundational quality implied by 'fundamental.' Rather, they suggest a level of sophistication, inclusion, or progression that diverges from the essence of being strictly basic or foundational.