The correct option is
B Tracheids
During the process of maturation, the cells undergo additional or secondary thickening deposition of new materials such as cellulose, lignin, suberin, cutin, etc. The deposition of lignin takes place in the form of rings on the inner surface of the cell wall. The gaps of the walls remain unthickened. Such thickenings are commonly found in the vessels and tracheids.
So, the correct answer is 'Tracheids.'