Describe the structure of mature phloem tissue. What are the unique features? What kind of problems do these features raise with respect to phloem translocation

In a woody tree with multiple years of growth, where would you look to find the youngest xylem tissues and the youngest phloem tissues in the cross section of a cut tree trunk? immediately inside the cork cambium and immediately outside the vascular cambium, respectively а. b immediately inside and immediately outside the vascular cambium, respectively immediately inside and immediately outside the cork cambium, respectively at the very center of the trunk and immediately outside the cork cambium, respectively d.

Explain 2 primary functions of plant stems. Also provide one example of a modified stem and explain why the modification has been selected for evolutionarily (what advantage does it provide?)

Which substances does the phloem transports?