"A graduate at 18, professor and associated editor of the Sudharak at 20, Secretary of the Sarvajanik Sabha and of the Provincial Conference at 25, Secretary of the National Congress at 29, leading witness before an important Royal Commission at 31, Provincial legislator at 34, Imperial legislator at 36, President of the Indian National Congress at 39......... a patriot whom Mahatma Gandhi himself regarded as his master." This is how a biographer describes

1. The question provides a biographical description highlighting key achievements and milestones, culminating in the person being regarded as Mahatma Gandhi's political master. 2. Let's analyze the milestones mentioned against the known biographies of the options: - Graduate at 18, professor at 20: Matches Gopal Krishna Gokhale's early academic career at Fergusson College. - Editor of the Sudharak: Gokhale was associated with this journal founded by Gopal Ganesh Agarkar. - Secretary of the Sarvajanik Sabha and Provincial Conference: Gokhale held these positions. - Secretary of the National Congress: Gokhale served as Joint Secretary. - Witness before a Royal Commission (Welby Commission): Gokhale famously testified before the Welby Commission on Indian expenditure in 1897 (age 31). - Provincial legislator, Imperial legislator: Gokhale was elected to the Bombay Legislative Council and later the Imperial Legislative Council. - President of the Indian National Congress: Gokhale presided over the Benares session in 1905 (age 39). - Regarded as Mahatma Gandhi's political guru/master: This is a well-known fact. 3. All these points strongly align with the life and career of Gopal Krishna Gokhale. The other leaders, while prominent patriots, do not match this specific sequence of achievements and the relationship with Gandhi.