Answer:

Background:
Warren Hastings was the first Governor-General of India, serving from 1773 to 1785. During his tenure, he introduced various reforms to improve the administration of British India. One of his significant contributions was the transfer of the treasury from Murshidabad to Calcutta.

Reasons for shifting the treasury:
There were several reasons for Warren Hastings to shift the treasury from Murshidabad to Calcutta, which are as follows:

1. Security: Murshidabad was the former capital of Bengal, and it was a vulnerable place as it was located on the banks of the river Bhagirathi. It was prone to floods and lacked security. In contrast, Calcutta was a safer place as it was situated on the banks of the Hooghly river, which was a branch of the Ganges.

2. Trade: Calcutta had become an important center of trade and commerce during the British rule. It had a large number of British merchants, who required financial assistance and a secure place to store their money. Hastings believed that shifting the treasury to Calcutta would increase trade and commerce.

3. Administration: Calcutta was the administrative capital of British India, and it made sense to shift the treasury there to improve the efficiency of the administration. The Governor-General and his council were located in Calcutta, and it was easier to manage the finances from there.

Impact of shifting the treasury:
The shifting of the treasury from Murshidabad to Calcutta had a significant impact on British India, which are as follows:

1. Economic growth: The transfer of the treasury to Calcutta led to the growth of trade and commerce. The merchants had easier access to funds, which enabled them to expand their businesses and invest in new ventures, leading to economic growth.

2. Administrative efficiency: The transfer of the treasury to Calcutta improved the efficiency of the administration. The Governor-General and his council could manage the finances more effectively, leading to better governance.

3. Migration: The shifting of the treasury to Calcutta led to the migration of people from Murshidabad to Calcutta. The British officials and merchants moved to Calcutta, leading to the growth of the city's population.

In conclusion, Warren Hastings' decision to shift the treasury from Murshidabad to Calcutta was a significant step towards the economic growth and administrative efficiency of British India. It enabled the British officials and merchants to manage their finances more effectively, leading to the growth of trade and commerce.