The correct option is B ii, iii
During spring, cambium is highly active and produces many xylary elements with wider cavity vessels, which form the springwood or earlywood. During wintertime, the cambium is not very active and creates less xylary components with thin vessels called autumn wood or latewood. The difference between springwood and autumn wood is that the former is lighter in color and has a lower density, whereas the latter is darker and has a higher density. They appear as alternate concentric circles and are produced in one year. These two bands make an annual ring. The age of a plant can be determined by counting the annual rings. It is called dendrochronology.