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📌 The Question:

Which one of the following is used in preparing a natural mosquito repellent?

(a) Congress grass
(b) Elephant grass
(c) Lemongrass
(d) Nut grass

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✅ Correct Answer: (c) Lemongrass

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🧠 Classroom Explanation:

Lemongrass contains citronella, a naturally occurring essential oil well known for its mosquito-repelling properties.

🔹 Citronella oil is:
• Extracted from lemongrass species
• Approved and registered by the US FDA
• Widely used in candles, sprays, coils, lotions, and vaporizers

🔹 The strong citrus fragrance of citronella interferes with mosquitoes’ ability to detect human scent, thereby repelling them.

🔹 This is why lemongrass plants are often grown:
• Near walkways
• Around seating areas
• In home gardens as a natural repellent

👉 Hence, lemongrass is correctly used in preparing natural mosquito repellents.

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🔍 Curiosity Raiser:
Did you know? 🌿
Citronella does not kill mosquitoes — it confuses their smell receptors, making humans “invisible” to them.

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📚 Enrich Notes (Prelims Edge):

• Citronella ≠ Insecticide → It is a repellent
• Congress grass → Invasive weed, allergenic
• Elephant grass → Biofuel, fodder crop
• Nut grass (Cyperus rotundus) → Medicinal weed, not repellent

Quick Elimination Trick:
👉 Mosquito repellent + fragrance = Citronella = Lemongrass

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🪶 IAS Monk Whisper:
Nature often protects us best when we learn its quiet chemistry.