The oldest part of phloem in a dicot stem is situated just
A) outside vascular cambium
B) inner to primary cortex
C) inner to vascular cambium
D) between periderm and primary cortex

The oldest part of phloem in a dicot stem is situated just inner to primary cortex.
The arrangement from inside towards outside (outside here means towards bark of plant) it as under: secondary phloem : primary phloem : cortex epidermis. Hence secondary xylem is present inside the cortex adjacent to primary phloem from outside to inside 
Hence, option (B) is correct.

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