In the diagram of a plant cell below, what is the function of the structure 4?

In the diagram we see a cell plant, with a few structures numbered:
0. Vacuole
,1. Chloroplast
,2. Nucleus
,3. Cell wall
The answer options correspond with the functions of these structures:
0. Vacuole- Has secretory, excretory, and storage roles (B)
,1. Chloroplast - It makes the photosynthesis (D)
,2. Nucleus - Serves as the control center of the cell and contains the genetic information (A)
,3. Cell wall ,- ,Provides structural support to the cell (C)