If \frac{m}{n}\equal{}\frac{4}{3} and \frac{r}{t}\equal{}\frac{9}{14}, the value of \frac{3mr\minus{}nt}{4nt\minus{}7mr} is:
(A)\ \minus{}5 \frac{1}{2} \qquad
(B)\ \minus{}\frac{11}{14} \qquad
(C)\ \minus{}1\frac{1}{4} \qquad
(D)\ \frac{11}{14} \qquad
(E)\ \minus{}\frac{2}{3}