The correct answer to the question is option 4, Lord Hardinge, who annulled the Partition of Bengal. The Partition of Bengal was an administrative reorganization carried out by Lord Curzon in 1905. This reorganization divided the Bengal Presidency into two separate provinces - Bengal and East Bengal and Assam. The main objective behind this decision was to weaken the growing nationalist movement in Bengal.

However, the partition was met with strong opposition and protests from the Indian nationalists, as it was seen as a deliberate attempt to divide and weaken the unity of the Bengali-speaking population. The decision was criticized for its political and economic implications, as well as its impact on Hindu-Muslim relations.

In response to the widespread discontent and protests, Lord Hardinge, who succeeded Lord Curzon as the Viceroy of India in 1910, annulled the Partition of Bengal in 1911. This decision was welcomed by the Indian nationalists and played a significant role in strengthening the nationalist movement in India.