Answer:
The correct option is A.
Step-by-step explanation:
Phloem is the conductive tissue responsible for the transport of organic nutrients, produced by photosynthesis. It is composed of two types of conductive cells: sieve tubes and companion cells, the first are responsible for sieve the structures, at the ends of the sieve tube elements, pores are formed, these small pores allow dissolved nutrients to travel through of the tube. On the other hand, the companion cells have nucleus and ribosomes and feed the sieve elements, these cells are responsible for maintaining and controlling these elements metabolically.