Question

Which cellular structure must substances pass through to enter or leave the cell?

a red blood cells
b nucleus
C cell membrane

Answer 1

C. The cell membrane

The cell membrane functions as a semi-permeable barrier, allowing a very few molecules across it while fencing the majority of organically produced chemicals inside the cell.

Step-by-step explanation:

Hope it helps! =D

Answer 2

Cell membrane, due to the cell membrane controlling what goes in and out of the cell.