To find the number of edges of a rectangular pyramid, we need to understand the structure of a rectangular pyramid and count the number of edges it has.

A rectangular pyramid is a three-dimensional shape with a rectangular base and four triangular faces that meet at a single point called the apex or vertex. It can be visualized as a pyramid with a rectangular base.

Let's break down the structure of a rectangular pyramid to count its edges:

1. Base:
- A rectangular pyramid has a rectangular base.
- A rectangle has four sides.
- Each side of the rectangle is an edge of the base.
- Therefore, the base of a rectangular pyramid has 4 edges.

2. Triangular Faces:
- A rectangular pyramid has four triangular faces.
- Each triangular face is formed by connecting one vertex (apex) to the three vertices of the base.
- Each triangular face has three edges.
- Therefore, the total number of edges from the triangular faces is 4 faces × 3 edges = 12 edges.

3. Apex:
- The apex of a rectangular pyramid is a single point where all the triangular faces meet.
- The apex does not have any edges.

Now, let's sum up the edges:

- Base edges: 4 edges
- Triangular faces edges: 12 edges
- Apex edges: 0 edges

Total edges = Base edges + Triangular faces edges + Apex edges
= 4 + 12 + 0
= 16 edges

Therefore, the correct answer is option 'B' - 8.