Identify the figure description given in the options, which when put in place of the question mark ($?$) will logically complete the series.

Let's analyze the pattern between consecutive boxes in the series:
Notice that the left (small) shape of Box $i$ becomes the right (large) shape of Box $i+1$:
* Box 1 left has a triangle $\to$ Box 2 right has a large triangle.
* Box 2 left has a narrow rectangle $\to$ Box 3 right has a large rectangle.
* Box 3 left has an hourglass shape $\to$ Box 4 right has a large barrel/hourglass shape.

Following this pattern, since Box 4 left has a small hexagon, Box 5 right must contain a large hexagon. Looking at the position conventions where the smaller element is on the left and the larger element is on the right, Option C perfectly satisfies this requirement by introducing a new small diamond shape on the left alongside the large hexagon on the right.