The Appearance of Annual Rings in Wood Is Created by Which

The appearance of annual rings in wood is created by which of the following?

A) smaller springwood cells and larger summerwood cells
B) heavily pigmented springwood cells and lightly pigmented summerwood cells
C) larger springwood cells and smaller summerwood cells
D) the presence of cells in springwood and the absence of cells in summerwood
E) vascular rays that extend to the cork cambium