Transport of  acid from mesophyll cells to the bundle sheath cell takes place through
a)	Cell membrane	b)	Cell wall	c)	Plasmodesmata	d)	Osmosis

(c)

Mesophyll cells and bundle sheath cells which are connected through plasmodesmata, through which organic acid like malic acid, pyruvic acid can translocate. Malic acid translocate from the mesophyll cells to bundle sheath cell and pyruvic acid translocate from the bundle sheath cells to mesophyll cells