East Champaran district is known for agricultural activities, though saffron is primarily cultivated in Jammu and Kashmir. This question tests regional knowledge of Bihar's agricultural areas.

The Kosi River is a tributary of the Ganges River. It originates in the Himalayas and flows through Bihar before joining the Ganges.

Sarnath is located near Varanasi in Uttar Pradesh, not Bihar. However, many other important Buddhist sites are in Bihar including Bodh Gaya and Nalanda.

Calculation: 10.3 crore × 63.8% = 10.3 × 0.638 = 6.5714 crore ≈ 6.6 crore (when rounded to nearest tenth crore).

Under Emperor Ashoka, the Mauryan Empire extended across the entire Indian subcontinent from the Himalayas to the Deccan Plateau, covering regions in all directions.

While Dinabandhu Mitra depicted the Indigo Revolt through his play 'Nil Darpan', the actual revolts were against indigo planters. The movement occurred in Bengal and Bihar regions against exploitative indigo cultivation.

Patna was known as Pataliputra during the Mauryan period. It was established as the capital by Chandragupta Maurya and became one of the largest cities in the ancient world.

Rajgir (Rajagriha) is mentioned frequently in Buddhist texts as a place where Buddha spent considerable time. It was the capital of the Magadha empire under King Ajatashatru.

Bihar shares the India-Nepal border in its northern region. West Champaran and East Champaran districts have significant sections of the Bihar-Nepal international boundary.

Nalanda University, located in Bihar, was one of the world's oldest universities and the most prestigious center of Buddhist learning from the 5th to 12th century CE. It attracted scholars from China, Japan, Korea, and Southeast Asia.