Which part of the plant cell is undifferentiated meristem cells flower and stem cells leaf and root cells phloem and xylem cells

The correct option is A, MERISTEM CELLS.
Undifferentiated cells refer to those cells which have not yet developed into a specific cell variant, that is, they are the very basic cell type. The meristem cells are undifferentiated cells from which all other cells are developed. Meristem cells are located in the growth zone of plants and they give rise to all organs of the plant.

Hold on to his or her beliefs even if there is no evidence for those beliefs.

Calcinosis is the diagnostic term that means an abnormal buildup of calcium on the kneecap (patellar) surface. it is a term uses to describe a group of disorders in which calcium deposits form in the skin. it is also referred to the abnormal deposit of calcium phosphate.