Final answer:
The correct answer is option A. a variety of corn that produces bacteria that are toxic to insects a form of corn that grows in.
Step-by-step explanation:
Bt corn, or Bacillus thuringiensis corn, is a genetically modified variety of corn that has been engineered to produce a toxin from a bacterium. This toxin acts as an insecticide, specifically targeting insects that feed on the corn plants.
The toxin is produced in the form of protein crystals during sporulation of the bacterium, and when ingested by the insects, it stops their feeding and eventually leads to their death.
Bt corn is considered safe for the environment, non-toxic to humans and other mammals, and has been approved for use by organic farmers as a natural insecticide.