In a ring girdled plant, what happens?

Girdling or ring barking is a process of removal of the phloem leading to the death of the plants and trees. The death occurs due to the inability of the leaves to transport sugars especially sucrose to the roots. If however, the xylem is also removed, the water and minerals also do not get transported leading to the death of the roots and eventually the tree. Therefore, the correct answer is option A. The shoot dies first because it relies on the phloem for sugars transported from the leaves. Removing the phloem disrupts this transport, leading to the shoot's death before the roots. While eventually the roots will also die due to lack of sugars, the shoot dies first.