Final answer:
In plant cells, plasmodesmata are the cellular junctions that allow for ion transport between cells.
Step-by-step explanation:
The cellular junction in plant cells that would allow for ion transport between cells is D. plasmodesmata. Plasmodesmata are channels between adjacent plant cells that are crucial for the movement of substances, including ions, nutrients, and other molecules necessary for intercellular communication. While gap junctions serve a similar function in animal cells, allowing for transport and communication, they are structurally different from plasmodesmata.