HORTICULTURE

Detailed explanation-1: -For example, palm trees increase their trunk diameter due to division and enlargement of parenchyma cells, which is termed as ‘diffuse secondary growth’.

Detailed explanation-2: -The increase in stem thickness is a type of secondary growth that is contributed by the activity of the lateral meristems.

Detailed explanation-3: -Secondary growth is characterized by an increase in thickness or girth of the plant. It is caused by cell division in the lateral meristem. Herbaceous plants mostly undergo primary growth, with little secondary growth or increase in thickness.

Detailed explanation-4: -Secondary growth occurs at the lateral meristems. The cells at the meristems undergo cellular division, where each cell multiplies into two daughter cells and add to the cellular material collectively called tissue. Secondary growth in plants produces secondary phloem and xylem.

Detailed explanation-5: -So, the correct answer is ‘vascular cambium’