The canary bird is used to detect ______ gas in the Singareni coal fields.

Carbon- Monoxide

The correct answer is Option (1) → Carbon-Monoxide

The canary bird was historically used in the Singareni coal fields, to detect the presence of carbon monoxide (CO) — a colorless, odorless, and toxic gas. Canaries are highly sensitive to carbon monoxide. If they showed signs of distress or died, it warned miners of the presence of the gas, allowing them to evacuate in time.

Note: This question is from pre rationailsed NCERT.