The correct answer is option 2, Lord Chelmsford. Jamshedpur was named after Jamsetji Nusserwanji Tata.

Option 1, Lord Hardinge, was the Viceroy of India from 1910-1916. Although he played a significant role in the governance of India, there is no evidence to suggest that he named Jamshedpur.

Option 3, Lord Irwin, was the Viceroy of India from 1926-1931. While he was involved in various reforms and policies, there is no indication that he named Jamshedpur.

Option 4, Lord Ripon, was the Viceroy of India from 1880-1884. Although he introduced certain administrative and political reforms during his tenure, there is no connection between him and the naming of Jamshedpur.

Therefore, the answer remains option 2, Lord Chelmsford, as he is attributed with naming the city after Jamsetji Nusserwanji Tata, the founder of the Tata Group.