Which of the following crops is described as – ‘It is a crop which is used both as food and fodder. It is a Kharif crop that requires temperature between 21°C and 27°C and grows well in old alluvial soil’?

The correct answer is Maize.

Let us analyze each characteristic mentioned in the description and match it to Maize step by step.

Step 1: "Used both as food and fodder"
Maize (also called corn) is a highly versatile crop. It is consumed as food by humans in many forms — boiled cobs, flour (makki ki roti), popcorn, cornflakes, and starch. At the same time, the entire plant — including its stalks, leaves, and husks — is used as fodder for livestock. This dual-purpose nature is a defining characteristic of Maize among the given options.

Step 2: "Kharif crop"
Kharif crops are sown at the beginning of the monsoon season (around June–July) and harvested by September–October. Maize is indeed a Kharif crop. It is sown with the onset of the monsoon and requires warm and moist conditions during its growing period — which perfectly matches the monsoon season in India.

Step 3: "Requires temperature between 21°C and 27°C"
Maize thrives in a warm climate. The ideal temperature range for its growth is between 21°C and 27°C. It cannot tolerate frost and needs adequate sunshine and warmth throughout its growing period. This temperature range rules out crops like Ragi, which can tolerate a wider range of temperatures including drier and hotter conditions.

Step 4: "Grows well in old alluvial soil"
Maize grows well in well-drained, fertile soils — particularly old alluvial soils found in river plains. Old alluvial soil (also called Bangar) retains nutrients and is found in elevated areas of river plains, making it suitable for Maize cultivation. Maize is widely grown in states like Uttar Pradesh, Bihar, Rajasthan, and Madhya Pradesh — all regions with significant alluvial soil cover.

Eliminating the other options:

• Sesame (Option 1): Sesame is an oilseed crop primarily used for oil extraction, not as fodder. It also prefers sandy loam or light soils rather than alluvial soil.
• Bajra (Option 3): Bajra (Pearl Millet) is indeed a Kharif crop and is used as food and fodder, but it grows best in sandy, arid soils and regions with very low rainfall — not in alluvial soils. It prefers much higher temperatures (around 25°C–35°C).
• Ragi (Option 4): Ragi (Finger Millet) is also a food and fodder crop, but it is mainly associated with red laterite soils and grows well in dry conditions in states like Karnataka and Tamil Nadu. It does not specifically require old alluvial soil.

Conclusion:
All four characteristics — dual use as food and fodder, Kharif season crop, temperature requirement of 21°C–27°C, and growth in old alluvial soil — collectively and uniquely point to Maize. No other option in the list satisfies all four conditions simultaneously.