If $x=-9$ and $y=-8$, evaluate the expression. \[ \frac{7-4 x}{y+8} \] Select the correct choice below and fill in any answer boxes within your choice. A. The answer is (Type an integer or a simplified fraction.) B. The expression is undefined.

Step 1 ：Given that $x=-9$ and $y=-8$, we are to evaluate the expression \[\frac{7-4 x}{y+8}\]

Step 2 ：Substitute $x=-9$ and $y=-8$ into the expression to get \[\frac{7-4(-9)}{-8+8}\]

Step 3 ：Simplify the expression to get \[\frac{7+36}{0}\]

Step 4 ：However, division by zero is undefined in mathematics. Therefore, the expression is undefined.

Step 5 ：Final Answer: \(\boxed{\text{undefined}}\)