4. Which of the following descriptions about "toxin in the environment" is INCORRECT? (A) The biological magnification is the toxin become more concentrated in trophic level of food web. (B) Chlorinated hydrocarbons has demonstrated biological magnification. (C) Some low toxic chemicals transform high toxic by exploring sunlight or microbial metabolism. (D) Chemicals released into the environment may be relatively harmless but converted to more toxic product by reaction with other substances, by exposure to light, or by the metabolism of microorganism. (E) WHO allows that DDT strictly reuse in disease vector control in 2007, so DDT is not environmental toxin anymore.