It is a common observation that members of Cucurbitaceae, like bottle-gourd, pumpkin, watermelon and musk melon, have large fruits while their stems are usually not more than a finger thick. What helps so much food to be translocated from leaves to the fruits for storage

A

Intraxylary phloem

B

Sieve-tubes with companion cells

C

Bicollateral vascular bundles

D

Trichomes on internodes