Consider the following statements regarding the regional history, geography, and various contexts of Bihar:

1. 1. The first session of the famous 'Bihar Student Conference' was held in 1906 at Bankipur, Patna, and was presided over by the eminent educationist and jurist Sir Dr. Sachchidananda Sinha.
2. 2. Vindhyan system rocks are found in the south-eastern plateau region of Bihar (hills of Kaimur and Rohtas), where vast reserves of sandstone, limestone, and pyrites are present, forming the mainstay of the state's mineral industry.
3. 3. When Bihar and Orissa were separated from Bengal to form a new province in 1912, Charles Stuart Bayley was appointed as its first Governor.
4. 4. 'Mandar Hill', located in Bhagalpur, surrounded by the mythological references of Mount Mandarachala and Vasuki Naga during the Samudra Manthan, is a monolith hill made of granite rock, with ancient remains associated with Jainism and Hinduism situated at its peak.

Which of the above statement(s) is/are completely true?