If Lignin-Containing Cell Walls Had Not Evolved in Land Plants

If lignin-containing cell walls had not evolved in land plants, we might now have

A) fields of tall plants that have rhizoids but lack stomata.
B) forests of tall animals instead of tall plants.
C) plants that grow underground instead of upward.
D) the same plant communities that we have now, because they would still have cellulose walls.
E) land areas of the planet covered with mats of low-lying plants and no trees.