The product of partial regression coefficient $$b_{12.3} b_{23.1} b_{31.2}$$ equals to:

A

$$\frac{r_{12.3} + r_{23.1} + r_{31.2}}{3}$$

B

$$\left({r_{12.3} r_{23.1} r_{31.2}}\right)^{\frac{1}{2}}$$

C

$$\frac{1}{r_{12.3}} + \frac{1}{r_{23.1}} + \frac{1}{r_{31.2}}$$

D

$${r_{12.3} r_{23.1} r_{31.2}}$$