The correct options are
B Investments were made by the British in India for their own gain.
C Establishment of railways, postal services and education was a part of the Financial phase.
The Financial phase was the third phase of colonialism in India. The East India Company wanted to keep the surplus profits with themselves and decided to make India its line of capital. So it began massive investments in railways, the postal system, irrigation, modern banking, and education to help increase profits.
The British received Diwani rights during the Industrial phase. It was this phase that was characterised by the production of goods.