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: Is the fort that Runyon took more than 2,000 pictures of still operational? Passage:Runyon opened a commercial photography studio in 1910. He initially photographed urban life Brownsville and Matamoros, Tamaulipas and the surrounding terrain of the Rio Grande Valley. In 1913, Runyon began recording the events of the Mexican Revolution, starting with the takeover of the Matamoros garrison by the Constitutional Army under General Lucio Blanco on June 3. He traveled with Blanco's forces to Ciudad Victoria and later Monterrey. In 1915, Runyon was the only professional to photograph two skirmishes by Mexican bandits on American soil, the Norias Ranch Raid and a train derailment near Olmito, Texas. He took more than 2,000 pictures of Fort Brown, which captured troop buildup and mechanization in preparation for World War I. Runyon returned to more traditional subjects in the border region, as well as portraits and postcards, following the end of the war.
 Links: a. Bandit War b. Fort Brown c. Rio Grande Valley d. Raid on Norias Ranch

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
b