The most effective fumigant employed for the fumigation in grain storage system is–

Correct option is C

• Phosphine (PH₃) is the most widely used and most effective fumigant for controlling insects and pests in stored grains worldwide. It is highly penetrative and lethal to a broad range of storage pests.
• Ethylene chloride is obsolete and not commonly used in food grain storage due to toxicity and regulatory restrictions.
• Hydrogen gas is not used as a storage fumigant.
• Carbon disulphide is flammable and less effective compared to phosphine, and it has largely been replaced by phosphine in modern practice.