The Vernacular Press Act was passed in 1878 during the tenure of Viceroy Lord Lytton. It sought to control and suppress the vernacular (local language) press in British India to curb criticism of British policies. The act caused significant controversy and was intensely opposed by many Indian leaders who valued press freedom as a cornerstone of democracy.

When the bill came up before the British Indian Legislative Council, only one Indian member was present. This individual was Jotendra Mohan Tagore. Tagore was an eminent personality of the era, known for his social and political contributions. Now let's understand why he was the correct answer:

1. Peary Mohan Mukherjea, Dinshaw Petit, and Dadabhai Naoroji: Although these individuals were notable figures in Indian politics and society, they were not the ones present when the Vernacular Press Bill was discussed.
2. Jotendra Mohan Tagore: He was the only Indian member of the Legislative Council during the discussion of this Act. His presence in the council highlighted the minimal representation Indians had in the legislative processes of the time.

Therefore, the correct answer is Jotendra Mohan Tagore, aligning historical records with this instance. Recognizing the role of individuals in historical legislative processes is crucial for understanding the broader impact of colonial policies on Indian society.