Which of the following figures will come in the missing place in the below figure?

The series displays geometric shapes with a decreasing number of sides (or edges):
* Second shape: Octagon ($8$ sides)
* Third shape: Hexagon ($6$ sides)

Following this arithmetic progression where each subsequent shape has $2$ fewer sides, the fourth shape must have:

$$6-2=4\text{ sides}$$

* Fifth shape: Semicircle / D-shape ($2$ sides: $1$ straight edge and $1$ curved edge)

Looking at the options:

* Figure (A) is a diamond/rhombus shape, which has exactly $4$ sides.
* Figure (B) is a heptagon ($7$ sides).
* Figure (C) and Figure (D) are triangles ($3$ sides).

Therefore, Figure (A) completes the pattern.