(D) Translocation
Translocation is the process by which soluble products of photosynthesis are transported in plants through phloem.
The key term here is translocation — transport of food (soluble products of photosynthesis) through phloem. Students often confuse it with transpiration (loss of water) or conduction (transport of water/minerals through xylem). Remember: xylem → water & minerals; phloem → food (translocation).