Who became the Nawab of Bengal in 1756 after the death of Alivardi Khan?

Correct option is A

Siraj Ud Daulah became the Nawab of Bengal in 1756 after the death of Alivardi Khan
 Alivardi Khan was the Nawab of Bengal from 1740 until his death in 1756.
 After his death, a succession dispute arose between his grandson Siraj Ud Daulah and his son-in-law Shaukat Jang. Siraj Ud Daulah emerged victorious and became the Nawab of Bengal.
 Siraj Ud Daulah's reign was marked by conflicts with the British East India Company, which led to the Battle of Plassey in 1757.
 The British emerged victorious in the battle and Siraj Ud Daulah was overthrown and later executed.