What is a theory

A)  a system of interrelated ideas used to explain a set of observations 
B)  an objective description of behaviour 
C)  the application of research to practical problems 
D)  a statement about the relationship between two or more variables

Interrelated Ideas

Concepts or thoughts that are connected in such a way that they influence or impact each other.

Observations

The action or process of closely monitoring or noting phenomena or data for the purpose of scientific inquiry or gathering information.

Theory

A set of concepts designed to elucidate a particular subject, founded on overarching principles unrelated to the subject matter itself.