The correct answer is option 'A' - British.

Explanation:
The institution of the Speaker and his role in the Indian Constitution are borrowed from the British Constitution. Let's understand this in detail:

1. Historical Background:
During the colonial rule, India was under British governance. The British had a parliamentary system of governance, and they introduced several democratic principles and institutions in India.

2. Role of the Speaker:
The Speaker is the presiding officer of the Lok Sabha, the lower house of the Indian Parliament. The Speaker is responsible for maintaining order in the House, conducting debates, and ensuring that the proceedings are conducted smoothly.

3. Borrowing from the British Constitution:
The institution of the Speaker and his role in the Indian Constitution is borrowed from the British Constitution. The British Parliament has a similar position called the Speaker of the House of Commons.

4. Similarities with the British Speaker:
a) Appointment: Just like in the British system, the Speaker in India is elected by the Members of Parliament.
b) Neutrality: The Speaker is expected to be impartial and maintain neutrality while conducting the proceedings.
c) Powers and Privileges: The Speaker enjoys certain powers and privileges to ensure the smooth functioning of the House.
d) Casting Vote: In case of a tie, the Speaker has the casting vote, which means he can exercise his vote to break the tie.

5. Differences:
Although the institution of the Speaker in India is borrowed from the British Constitution, there are some differences between the two systems:
a) Removal: In the British system, the Speaker holds the position until retirement, while in India, the Speaker can be removed by a resolution passed by a majority of the members.
b) Eligibility: In India, the Speaker must be a member of the Lok Sabha, while in the UK, the Speaker does not need to be an elected member of the House of Commons.

In conclusion, the institution of the Speaker and his role in the Indian Constitution are borrowed from the British Constitution. The British parliamentary system served as a model for the Indian Constitution, and the Speaker's position is one of the many democratic institutions that were adopted from the British system.