Answer:d. interrupting the passage of phloem sap and killing the tree.
Explanation:plants contains vascular bundles for conducting water and salt and dissolved food , throughout the plant.the vascular bundles; xylem and phloem are located close to the bark of the tree.
Girdling a tree involves cutting a deep groove all the way around a tree trunk.this is done to kill the tree.the phloem is removed along with the back of the tree.the xylem might remain intact.the phloem functions primarily to move food materials from one part of the tree to another.when it is removed,food materials produced in the leaves cannot get to the root.
After a while ,the root dies and so does the tree