$A$ $100$-year-old tree which shows well-marked annual rings in its trunk will have:

• A
  An irregular number of annual rings which may increase or decrease all along the length of the stem.
• B
  More than $100$ annual rings at the base and only about $50$ rings at the apex.
• C
  Only about a $100$ annual rings at the base and a uniformly decreasing number of annual rings towards the apex.
• D
  The same number of annual rings from the base of its trunk to its apex.