To simplify the given expression, we need to factor the numerator and the denominator and then simplify the fraction by canceling out any common factors.
The numerator can be factored as follows:
\begin{align*}
2x^2 - 5x - 12 &= 2x^2 - 8x + 3x - 12 \\
&= 2x(x - 4) + 3(x - 4) \\
&= (2x + 3)(x - 4)
\end{align*}
The denominator can be factored using the difference of squares formula as:
\begin{align*}
4x^2 - 9 &= (2x)^2 - 3^2 \\
&= (2x - 3)(2x + 3)
\end{align*}
Now we can simplify the fraction as follows:
\begin{align*}
\frac{2x^2 - 5x - 12}{4x^2 - 9} &= \frac{(2x + 3)(x - 4)}{(2x - 3)(2x + 3)} \\
&= \frac{x - 4}{2x - 3}
\end{align*}
Therefore, the simplified form of the expression is \(\frac{x - 4}{2x - 3}\). So, option (B) is the correct answer.