please answer this questioned in a detailed manner. Thank you for your time/effort! :)

| 2. We identified the paradigms (seminal models or theories in finance) as: a. MPT (Markowitz) I b. CAPM (Sharp, Lintner and Massin) c. EMH (Fama) d. Agency theory (Jensen and Meckling) e. OPT (option pricing theory Black, Scholes and Merton) f. Behavioral theory All of these theories have helped develop the field of finance. My question is what is the unifying theme in finance that ties all of these theories together to form a coherent goal or rationale