Turgor Pressure, Which Causes Cells to Expand, Results in a Force

Turgor pressure, which causes cells to expand, results in a force applied uniformly to the entire cell wall. How is it that plant cells are often observed to expand in a particular direction-for example, increasing their length but not their girth?

A) Cell shape follows the shape of the vacuole, which occupies up to 90% of the cell volume .
B) The expansion of the cell wall is controlled only where new material is deposited internally, thereby giving the cell precise control of its shape .
C) Cellulose molecules individually resist extension, and so the cell wall stretches more readily in directions perpendicular to the dominant orientation of cellulose molecules .
D) A cell's cytoskeleton imposes its shape on the flexible cell wall "skin," and so elongation of the cell follows the extensive growth of the cytoskeleton