Concept:Squirrels damage the tree's vascular tissues, especially by eating away the bark layer, which disrupts essential transport and growth.
Explanation:Squirrels do not inject poison but gnaw the bark around the trunk and branches.
This action removes or destroys the phloem and cambium tissues present beneath the bark.
The phloem is responsible for moving food from leaves to other parts of the tree.
The cambium is the growing layer that produces new cells for the tree's thickness.
When these tissues are damaged, food transport stops and new growth is blocked.
Because a tree cannot heal or transport nutrients effectively, it weakens and eventually dies.
This kind of damage is known as girdling, and it can kill even mature trees.
Thus, the correct option is the one that states squirrels gnaw the bark and destroy it.
Answer:D. they gnaw the bark and destroy