Lord Sinha had resigned in 1921 from the post of Governor of –

The correct answer is: A. Bihar-Orissa

Lord Sinha was the first Indian to be appointed as the Governor of a British Indian province. He served as the Governor of Bihar and Orissa from 1912 to 1921. He resigned from the post in 1921 due to ill health.

The other options are incorrect because:

• Lord Sinha was never the Governor of Bengal.
• Lord Sinha was never the Governor of Punjab.
• Lord Sinha was never the Governor of Madras.

I hope this helps!