After a biology field trip, you make a thin section of a flowering plant stem. You observe these two main sets of cells: the lower set of cells are large, have thick walls, and test positive for the lignin molecule, while the smaller, but uniform red cells do not have lignin. From this evidence, you conclude that the larger cells with lignin are

A. cuticle.
B. stomata.
C. rhizoids.
D. xylem.
E. phloem.

D. xylem

Explanation:

Xylem cells are specialized cells that possess a secondary cell wall that contains the chemical substance known as lignin. These molecules of this chemical compound that are produced in xylem cells, together with cellulose, provide strength to the plant. The lignin molecules found in xylem cells also helps in movement of water through the plant.

wegner's theory did not explain how the continents could move

explanation: