Which act established the supremacy of the Presidency of Bengal over the other two presidencies of Madras and Bombay; unlike earlier when the three presidencies were independent of each other under their respective governors?

Provisions of the Regulating Act:

1. The Act limited Company dividends to 6% until it repaid a £1.5M loan and restricted the Court of Directors to four-year terms.
2. It prohibited the servants of company from engaging in any private trade or accepting presents or bribes from the natives.
3. The Act elevated Governor of Bengal Warren Hastings to Governor-General and subsumed the presidencies of Madras and Bombay under Bengal's control. (Therefore, option '1' is correct)
4. The Act named four additional men to serve with the Governor-General on the Calcutta Council:  Lt-Gen John Clavering, George Monson, Richard Barwell and Philip Francis. Barwell was the only one with previous experience in India. These councilors were commonly known as the "Council of Four".
5. A supreme court was established at Fort William at Calcutta. British judges were to be sent to India to administer the British legal system that was used there.