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 the maximum length of the species that is known to prey on the crossback stingaree? Passage:The broadnose sevengill shark (Notorynchus cepedianus) is known to prey on the crossback stingaree. When threatened, this ray raises its tail warningly above its body in a scorpion-like fashion. Parasites documented from this species include a tapeworm in the genus Acanthobothrium, and the monogenean Calicotyle urolophi. Like other stingrays, the crossback stingaree is aplacental viviparous: when the developing embryos exhaust their supply of yolk, their mother provisions them with nutrient-rich histotroph ("uterine milk") through specialized extensions of the uterine epithelium called "trophonemata". Females produce litters of 14 pups every other year. Embryonic development proceeds rapidly over a six-month period, though the total gestation period may be much longer if there is a period of dormancy for the eggs after fertilization, as has been reported in other stingarees. Off Tasmania, large estuaries such as at the mouth of the River Derwent serve as nursery areas.

Example Output: b

Example Input: Question: How many students did Wellington College have the year that Vincent was promoted to lieutenant? Passage:Born the son of Colonel Arthur Hare Vincent and Elizabeth Rose Manson and educated at Wellington College and the Royal Military Academy, Woolwich, Vincent was commissioned into the Royal Artillery as a second lieutenant on 24 July 1891. He was promoted to lieutenant on 24 July 1894 and to captain on 13 February 1900. He served with the China Expeditionary Force in late 1900 and then in the Second Boer War in South Africa. Following the end of the war, Vincent left Point Natal for India on the SS Ionian in October 1902 with other officers and men of the J Battery Royal Horse Artillery, and after arrival in Bombay, was stationed in Meerut, Bengal Presidency. In 1903, Vincent was sent to Tokyo to learn Japanese: he served as British military attache with the Japanese Army during the Russo-Japanese War and, from 1 March 1904, was attached to the 2nd Division of the First Japanese Army in Manchuria.

Example Output: a

Example Input: Question: When did the river in which Major Long took an 1823 expedition change it's name? Passage:Major Long's 1823 expedition up the Minnesota River (then known as St. Peter's River), to the headwaters of the Red River of the North, down that river to Pembina and Fort Garry, and thence by canoe across British Canada to Lake Huron is sometimes confused with his initial expedition to the Red River in modern-day Texas and Oklahoma. The expedition to the Red River of the North was a separate, later appointment which completed a series of explorations conceived of by Lewis Cass and implemented by David B. Douglass, Henry Schoolcraft, and others besides Major Long. The 1823 expedition was denoted primarily as a scientific reconnaissance and an evaluation of trade possibilities, but probably had undisclosed military objectives as well, and certainly was viewed with suspicion by British authorities in Canada. This expedition for a time was joined by the Italian adventurer Giacomo Beltrami, who argued with Long and left the expedition near Fort Garry. The 1823 expedition encouraged American traders to push into the fur trade in Northern Minnesota and Dakota, and fostered the development of the Red River Trails and a colorful chapter of ox cart trade between the Red River Colony and Fort Garry via Pembina and the newly developing towns of Mendota and St. Paul.

Example Output:
b