Rotate the Axes to Eliminate The $x y$ -Term in the Following Equation and Then Write the Equation

Rotate the axes to eliminate the $x y$ -term in the following equation and then write the equation in standard form.
$$7 x ^ { 2 } - 28 x y + 28 y ^ { 2 } + 35 \sqrt { 5 } y + 7 = 0$$

A) $\left( x ^ { \prime } - 1 \right) ^ { 2 } = 7 \left( y ^ { \prime } - \frac { 4 } { 5 } \right)$
B) $\left( x ^ { \prime } + 7 \right) ^ { 2 } = - 5 \left( y ^ { \prime } + \frac { 1 } { 7 } \right)$
C) $\left( y ^ { \prime } + 1 \right) ^ { 2 } = - \left( x ^ { \prime } - \frac { 4 } { 5 } \right)$
D) $\left( y ^ { \prime } - \frac { 4 } { 5 } \right) ^ { 2 } = 7 \left( x ^ { \prime } - 1 \right)$
E) $\left( y ^ { \prime } + \frac { 4 } { 5 } \right) ^ { 2 } = x ^ { \prime } + \frac { 1 } { 7 }$