Given the task definition and input, reply with output. In this task, you're given a question, a context passage, and four options which are terms from the passage. After reading a passage, you will get a brief understanding of the terms. Your job is to determine by searching and reading further information of which term you can answer the question. Indicate your choice as 'a', 'b', 'c', or 'd'. If you think more than one option is plausible, choose the more probable option to help you answer the question.

Question: How old was the person who influenced Abani to join the revolutionary movement when they met? Passage:In 1914, Mukherji met Rash Behari Bose and joined the revolutionary movement. In 1915, he was sent to Japan to acquire weapons for the revolutionaries. According to British intelligence reports, he was active in the HinduGerman conspiracy. In September 1915, while on his return journey to India, he was arrested in Singapore and incarcerated at the Fort Canning prison there, where he remained until he escaped in the autumn of 1917. The exact details of his escape are unclear. Mukherji managed to reach Java in the Dutch East Indies, where he stayed until the end of 1919, living under the name of Dar Shaheer. In Java, he was in contact with Indonesian and Dutch revolutionaries and became a communist. He also travelled to Amsterdam and back. In Amsterdam, he met S.J. Rutgers, who recommended him as a delegate to the Second Congress of the Communist International.
Links: a. Rash Behari Bose b. Singapore c. S. J. Rutgers d. Communism
a