Solution
Option 1 -> Annie Besant was a political activist whose lectures Bharati attended in Banaras, but the passage doesn't indicate she directly inspired his commitment to India's liberation.
Option 2 -> Sister Nivedita's meeting with Bharati in 1906 is described as a "landmark event" after which "He pledged himself to the political liberation of India, the eradication of casteism and the emancipation of women."
Option 3 -> Swami Vivekananda was Sister Nivedita's guru, but Bharati didn't meet him directly according to the passage.
Option 4 -> Sri Aurobindo taught Bharati about Vedas and Vedantic Humanism in 1910, which was a spiritual/philosophical influence rather than the catalyst for political commitment.
Hence, Option 2: Sister Nivedita -> The passage explicitly states that Bharati's 1906 meeting with Sister Nivedita "proved to be a landmark event" and immediately after this meeting, "He pledged himself to the political liberation of India, the eradication of casteism and the emancipation of women" - clearly indicating she was the inspiration for his commitment to political and social liberation. -> correct