Detailed Explanation:

Shri Krishna Singh formed the first elected government in Bihar in July 1937 after the provincial elections under the Government of India Act, 1935.

The ministry resigned in February 1938 in protest against the British Government's refusal to release political prisoners, particularly those involved in the freedom movement.

This resignation was part of a broader pattern where Congress ministries in various provinces pressured the British administration on the issue of political prisoner release, though most ministries continued until October 1939 (resignation over India's involvement in World War II without consultation).