Find the missing term in the following expression. \[{{\left( \frac{3x}{4}-\frac{4y}{3} \right)}^{2}}=\frac{9{{x}^{2}}}{16}+\_\_\_\_\_+\frac{16{{y}^{2}}}{9}\]

• A.       \[2xy\]     
• B.  \[-2xy\]     
• C.    \[12xy\]    
• D.      \[-12xy\]