Question

current attempt in progress
basic research is best defined as research that
explores only one field of study.
solves simple problems encountered by humans and animals in a complex world.
is independent of other disciplines.
advances core scientific knowledge.

Explanation:

Basic research aims to expand fundamental knowledge. It's not limited to one field (so "explores only one field of study" is wrong). It's not about solving simple problems (so "solves simple problems..." is wrong). And it often interacts with other disciplines (so "is independent of other disciplines" is wrong). Its main goal is to advance core scientific knowledge.

Answer:

advances core scientific knowledge.