During which phase of growth, cell increases in volume

In plants, the growth is divided into three main phases, namely phase of cell division, cell enlargement and cell maturation. The phase of cell division is called as formative phase. The second phase is phase of enlargement. In this, cell enlargement and cell differentiation takes place. During this phase, cell increases in volume as cell size increases but cell number remains the same. The last phase is maturation phase. In this, cell differentiate into distinct type of cells and tissues. 

Thus, the correct answer is option D