Which place was called the "Nursery of the Bengal Army" during 1857?

Awadh

The correct answer is Option (3) → Awadh

Awadh was called the "Nursery of the Bengal Army" in 1857.

The large majority of the sepoys of the Bengal Army were recruited from the villages of Awadh and eastern Uttar Pradesh. Many of them were Brahmins or from the “upper” castes. Awadh was, in fact, called the “nursery of the Bengal Army’’.