Why, in Genetic Engineering, Are Plant Hybridization and Horizontal Gene

Why, in genetic engineering, are plant hybridization and horizontal gene transfer in bacteria a potential problem?

A) A natural plant or bacteria cell crossing with a genetically engineered organism will eliminate whatever trait was engineered in and the genetically engineered organism will be lost.
B) Plant hybridization and gene transfer both interfere with the protein making ability of the genetically engineered genes.
C) If gene transfer takes place between hybridized plants, there may be environmental consequences.
D) Plant hybridization and gene transfer between natural and genetically engineered organisms can release the engineered genes into the environment with potentially risky consequences.
E) Plant hybridization and gene transfer prevents genetically engineered organisms from producing proteins so they are useless.