In the Standard Model of the Expansion of the Universe,the $\rho _ { c } = \frac { H ^ { 2 } } { 8 \pi G }$

Multiple Choice

In the standard model of the expansion of the universe,the total energy of a standard mass m is assumed to be zero.When we solve the resulting energy equation for the critical mass density of the universe,we find that the critical mass density is given by

A) $\rho _ { c } = \frac { H ^ { 2 } } { 8 \pi G }$ .
B) $\rho _ { c } = \frac { 3 H ^ { 2 } } { 8 \pi G }$ .
C) $\rho _ { c } = \frac { 3 H ^ { 2 } } { 2 \pi G }$ .
D) $\rho _ { c } = \frac { 3 H ^ { 2 } } { \pi G }$ .
E) $\rho _ { c } = \frac { 3 H ^ { 2 } } { G }$ .