Why are cell walls porous? to help cells stick together
to absorb substances like a sponge
to help give cells structure and support
to allow chemicals to get through the walls easily

Primary walls are usually sufficiently permeable to allow the movement of water and solutes oflow Mr (relative molecular mass) from the outside of the cell to the plasma membrane, or past cells and through tissues within the apoplast (the connected wall space of adjacent cells).

so it's the 3rd

to help give cells structure and support

Explanation: