Answer:
The correct option is C. The rigidity of a cell wall causes plants to be sedentary.
Step-by-step explanation:
One of the important functions of the cell wall is to provide rigidity to the plants. As the plant cell walls are rigid, they make the plant sedentary. The animal cells lack a cell wall and hence are flexible enough for locomotion. Hence, option C is correct.
Other options are false because:
OPTION A: In a wilting plant, the vacuole will shrink and not be full.
OPTION B: Primary cell walls are not more rigid than the secondary cell walls.
OPTION C : Plant cells do have cell membranes.