Pataliputra (modern Patna) was the capital of the Mauryan Empire under Chandragupta Maurya, Bindusara, and Ashoka. It was one of the largest cities of ancient India.

The Ganges River enters Bihar from Uttar Pradesh and flows eastward through the state before entering West Bengal.

The Mahabodhi Temple Complex at Bodh Gaya is a UNESCO World Heritage Site. It dates back to the 5th-6th century and is one of the finest examples of brick temple architecture.

The area of Bihar is approximately 94,163 square kilometers, making it the 13th largest state in India by area. It is one of the most densely populated states.

Vaishali was the capital of the Lichchhavi republic, one of the earliest known republics in the world. It was also an important center during the time of Buddha and Mahavira.

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.

While the Darbhanga Raj Palace was primarily developed by the Darbhanga Rajas during British rule, Shah Jahan's administration oversaw significant construction in Bihar. The palace is one of Bihar's most significant architectural structures.

Bakhtiyar Khilji, an Islamic general, attacked Nalanda University around 1193 CE and destroyed much of its library and infrastructure, leading to its decline.