Determine the Constants (Denoted with Capital Letters) So That the Equation

Multiple Choice

Determine the constants (denoted with capital letters) so that the equation is an identity. $\frac { 8 x + 3 } { ( x + 3 ) ^ { 2 } } = \frac { A } { x + 3 } + \frac { B } { ( x + 3 ) ^ { 2 } }$

A) $\begin{array} { l } A = 7 \\B = 21\end{array}$
B) $\begin{array} { l } A = 7 \\B = 22\end{array}$
C) $\begin{array} { l } A = - 8 \\B = - 21\end{array}$
D) $\begin{array} { l } A = 8 \\B = - 21\end{array}$
E) $\begin{array} { l } A = - 8 \\B = 21\end{array}$