Q.What is DDT among the following:

DDT (p,p'-dichlorodiphenyltrichloroethane, IUPAC 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane) was first prepared in 1873, but its effectiveness as an insecticide was only discovered in 1939 by Paul Muller, who won the 1948 Nobel Prize in Medicine and Physiology for the finding. It is made by heating chlorobenzene with chloral (trichloroacetaldehyde) in concentrated H2SO4, condensing two chlorobenzene rings onto the chloral carbon. Its uses were genuinely transformative -- controlling insect vectors of malaria and yellow fever, protecting farm crops from agricultural pests, pest control in building construction, and killing household insects such as houseflies and mosquitoes owing to its high, specific toxicity -- but DDT is now banned in most countries because it is extremely chemically stable and barely biodegradable, so it persists in soil and water for years, bioaccumulates up the food chain in fatty tissue, and famously thins the eggshells of birds of prey, alongside long-term toxicity concerns for other wildlife and for hu …