Answer:
The correct answer would be allergies.
Allergies is one of the common disadvantages of recombinant DNA technology.
It has been observed that use of genetically modified crops can cause life-threatening allergies.
The possible reason is that the introduction of new genes in the crops may lead to the formation of new proteins our body has never encountered with. These proteins may have a potential to cause allergies or any other life-threatening diseases or complications.