Question

what is the main function of cytoplasm in a plant cell?
to control which substances enter and leave the cell
to make proteins
to fill the space between the cell membrane and the nucleus
to direct cell activities by sending instructions to different parts of the cell

Explanation:

Cytoplasm is a gel - like substance within the cell. The cell membrane controls substance entry/exit. Ribosomes make proteins. The nucleus directs cell activities. Cytoplasm fills the space between the cell membrane and nucleus.

Answer:

to fill the space between the cell membrane and the nucleus