Which one of the following statements is accurate?
a. wheat, corn, soybeans, and cabbage are the main four plants responsible for providing food to people in the world.
b. agriculture has been challenged by the use of selective breeding.
c. gymnosperms provide humans with the most food.
d. the green revolution was instrumental in the increase of the world's food supply.

The periodic table houses noble gas elements in group 18. these elements are highly stable and rarely react with any other elements. what is one possible reason for the stability of the noble gas elements? a. they easily form covalent bonds. b. the compounds that they form with other elements are very unstable. c. their outermost shell has the maximum number of electrons that it can hold. d. they require less activation energy.