You Are Asked to Determine Whether an Unknown Tissue Specimen

You are asked to determine whether an unknown tissue specimen comes from a plant or an animal. Closer inspection with an electron microscope reveals that the cells are connected by small openings lined by extensions of the cell membrane and containing tubules connecting the endomembrane systems of adjacent cells. Which of the following conclusions can you draw from your observations?

A) The openings are plasmodesmata, so the tissue must come from a plant.
B) The openings are plasmodesmata, so the tissue must come from an animal.
C) The openings are gap junctions, so the tissue must come from a plant.
D) The openings are gap junctions, so the tissue must come from an animal.
E) The openings could be either gap junctions or plasmodesmata, so it cannot be determined whether the tissue came from a plant or an animal.