Age of a tree may be ascertained by A. Radius of its stem B. Circumference of its stem C. Number of branches D. Number of annual rings

The correct answer is D. Number of annual rings.

Annual rings are visible in the cross-section of a tree trunk. They are formed each year as the tree grows, and each ring represents one year of growth. The number of annual rings can be used to determine the age of a tree.

The radius of a tree’s stem is the distance from the center of the stem to the outside edge. The circumference of a tree’s stem is the distance around the stem. The number of branches on a tree can vary depending on the species of tree and the environment in which it is growing.

All of these factors can affect the growth of a tree, but the number of annual rings is the most reliable way to determine its age.