Introduction:
Ryotwari Settlement was a system of land revenue collection introduced by the British during their rule in India. It was implemented in the Madras Presidency and some parts of Bombay and Assam. This settlement system involved direct interaction between the British government and individual farmers or ryots. The system aimed to establish individual ownership and transferability of land rights.

Lord Cornwallis:
- Lord Cornwallis was the Governor-General of India from 1786 to 1793.
- He introduced the Permanent Settlement in Bengal, Bihar, and Odisha, which was a different system of land revenue collection.
- The Permanent Settlement was not successful and led to the accumulation of power and wealth in the hands of a few zamindars (landlords), resulting in the exploitation of the peasants.
- Lord Cornwallis is not associated with the introduction of Ryotwari Settlement. Therefore, option 1 is incorrect.

Alexander Read:
- Alexander Read was a British civil servant who served in the Madras Presidency.
- He played a significant role in the introduction and implementation of the Ryotwari Settlement system.
- Read was appointed as the Collector of Coimbatore in 1804 and later became the Commissioner of Revenue and Circuit in 1807.
- He developed the Ryotwari Settlement system based on the principles of individual ownership, assessment of land revenue based on crop productivity, and periodic revision of assessments.
- Alexander Read's contribution to the introduction of Ryotwari Settlement makes option 2 correct.

Thomas Munro:
- Thomas Munro was a British colonial administrator who served in the Madras Presidency.
- He played a crucial role in the implementation and expansion of the Ryotwari Settlement system.
- Munro served as the Collector of Bellary and Cuddalore and later became the Governor of Madras Presidency.
- He made significant reforms in the Ryotwari Settlement system, including the introduction of the "Patta" system, which provided legal documentation of land rights to the ryots.
- Thomas Munro's association with the introduction and development of the Ryotwari Settlement system validates option 3.

Conclusion:
Based on the above analysis, it can be concluded that both Alexander Read and Thomas Munro were associated with the introduction of Ryotwari Settlement in India during the British rule. Therefore, the correct answer is option B (2 and 3 only).