In this task, you're given a question, along with a context passage. The passage will not have a direct answer to the question, but can include some information and a clue for the answer. Assuming you can only obtain information about one entity in the passage, your job is to determine whether information from the passage can be used to answer the question. Indicate your choice as `a` for Yes or `b` for No.

Example Input: Question: What is one key difference between the Indus Valley civilization and early Vedic civilizations? Passage:The book discusses four prehistoric migrations in India. The book mentions that the Harappans were a mixture of Zagros agriculturists and First Indians, a wave of migrants who came from Africa into Arabia and then reached India around 65,000 years ago. Citing recent DNA evidence, the book traces the subsequent large migrations of anatomically modern humans into India—of agriculturalists from Iran between 7000 and 3000 BCE and Indo-European languages speaking pastoralists from the Central Asian Steppe (Aryans) between 2000 and 1000 BCE, among others. Tony Joseph used pizza as a metaphor to explain the break-up of subcontinental society. The book also discusses about similarities and differences between Indus Valley civilization and early Vedic civilization. The book mentions that ‘Aryan’ culture was most likely the result of interaction, adoption and adaptation among those who brought Indo-European languages to India and those who were already well-settled inhabitants of the region, and that Sanskrit and Vedas developed in the Indian subcontinent. Various tribes like the Andamanese and the Semang (Malay Peninsula), the Mani (Thailand) and the Aeta people (the Philippines) were the earliest inhabitants of Southeast Asia. According to Joseph, Proto-Dravidian is related to the Elamitic language of Iran. Caste system in India is a recent social system, reflected in sharply reduced inter-marriage (endogamy) and genetic mixing after 100 AD. This book also takes into account the path-breaking DNA research and findings from geneticist David Reich's research.

Example Output: a

Example Input: Question: How many soldiers did Britain send to World War I the year Roebuck arrived on the Western Front? Passage:As a boy, Roebuck worked as a trammer and after being sentenced to one month's imprisonment for stealing a watch in 1904, he enlisted in the York and Lancaster Regiment. Over the next seven years, he was stationed in India and Ireland and was promoted to lance corporal, but was demoted back to private in 1910 for "misconduct". He married in 1908 and had two children. Roebuck was discharged into the reserves in 1912 and likely returned to work as a miner prior to becoming a professional footballer in 1913. After Britain's entry into the First World War in August 1914, he was called up by the York and Lancaster Regiment and arrived on the Western Front in September 1914. On 18 October 1914, Roebuck recorded as "presumed dead" after an attack near Beaucamps-Ligny during the Race to the Sea. His death was confirmed by two comrades in January 1915. Roebuck is commemorated on the Ploegsteert Memorial to the Missing.

Example Output: a

Example Input: Question: What king was overthrown during the July Revolution? Passage:The last meetings had revealed the rising antagonism with Britain and France, especially on Italian unification, the right to self-determination and the Eastern Question. The Alliance is conventionally taken to have become defunct with Alexander's death in 1825. France ultimately went her separate way after the July Revolution of 1830, leaving the core of Russia, Austria and Prussia as Central-Eastern European block which once again congregated to suppress the Revolutions of 1848. The Austro-Russian alliance finally broke up in the Crimean War: though Russia had helped to completely destroy the Hungarian Revolution of 1848, Austria did not take any action to support her ally, declared herself neutral and even occupied the Wallachian and Moldavian lands on the Danube upon the Russian retreat in 1854. Thereafter, Austria remained isolated, which added to the loss of her leading role in the German lands, culminating in the defeat of the Austro-Prussian War in 1866.

Example Output:
b