Read the following passage and mark the letter A, B, C, or D to indicate the correct answer to each of the questions from 30 to 34.

The popularity of organic foods can be traced to many people’s nostalgia for a simpler, more pioneer-like life style. And many people believe that organic foods are safer than foods produced on a large scale by traditional methods. Many people also believe that these organic foods contain more and better nutrients than conventional food.

       In fact, plants absorb all their food directly from the soil in inorganic form, no matter where the nutrients may originally have come from. Experiments in Michigan and in England that went on for twenty-five years were unable to find any difference in plants raised organically and plants raised with chemical fertilizers. Things that do affect nutrient content are climate, time of harvest, and genetics - but no difference results when plants are grown organically.

       Neither are organically grown plants free from chemicals such as pesticides. Some pesticides leave traces in the soil for years; these traces may be absorbed by the plant that is “organically” grown. Rainfall may wash pesticides from neighboring farms onto “organic” fields, and sprays or other applications of chemicals may drift and cause the same problem.

       Furthermore, all foods - whether grown conventionally or organically - may contain toxic substances to some degree; the Food and Drug Administration (FDA) maintains constant checks to ensure that these substances are kept at a harmless level. But aflatoxin, a mold that causes cancer, may grow on crops such as peanuts, or be present in milk. Lead and arsenic are sometimes present in bone meal or seafood. And many vegetables contain poisonous compounds such as oxalic acid and nitrite compounds. The point is, all these toxins may be present in a given food, no matter how the food was grown and cultivated. Toxic substances in food do not necessarily have to come from fertilizers or chemical sprays.

This passage is mainly about _____.

• A. 
  the rise in demand for organic food in the last decade
• B. 
  how organic plants are grown in different kinds of soil
• C. 
  the toxic substances contained in both organically and inorganically grown food
• D. 
  the numerous fallacies that exist about organically grown foods