The question asks for the width of a rectangle, given that the area is 63 square meters and the length is 9 meters.

We know that the area $A$ of a rectangle is given by the formula:

$A = \text{length} \times \text{width}$

Substituting the known values:

$63 = 9 \times \text{width}$

To solve for the width, divide both sides by 9:

$\text{width} = \frac{63}{9} = 7 \, \text{meters}$

Thus, the correct answer is $\boxed{7}$, which corresponds to option A.

Would you like further details or have any questions?

Here are five relative questions to expand on this:

1. How do you calculate the perimeter of a rectangle?
2. What is the area formula for a triangle, and how does it differ from that of a rectangle?
3. If the width were doubled, what would the new area be?
4. What are the units of area, and why are they squared?
5. How can you calculate the diagonal of a rectangle using the Pythagorean theorem?

Tip: Always double-check units when working with area or volume, as they can change based on the type of measurement (e.g., meters vs. square meters).