Which of the following was actually used as an insecticide in the 1920s and 1930s?

• A. Heroin
• B. Cocaine
• C. Nicotine
• D. Alcohol

Answer: (C)

Verified step by step guidance

1. Begin by understanding the historical context of the use of substances as insecticides. In the early 20th century, various chemicals were explored for their effectiveness in pest control.
2. Recognize that nicotine, derived from tobacco plants, was known for its toxic properties to insects and was used as an insecticide during the 1920s and 1930s.
3. Consider the properties of nicotine that make it effective as an insecticide. Nicotine affects the nervous system of insects, leading to paralysis and death.
4. Reflect on why other substances listed, such as heroin, cocaine, and alcohol, were not used as insecticides. These substances do not have the same toxic effects on insects as nicotine does.
5. Conclude by noting the transition from natural insecticides like nicotine to synthetic ones in later years, as chemical research advanced and new compounds were developed.