Definition: 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.
Input: Question: What is the population of the municipality where the USS St Louis was built in 1861? Passage:The USS Essex had been constructed in 1856. She was a 1000-ton river gunboat, converted from her original role as a timberclad ferry named New Era. She was armed with one 32-pounder cannon, three Dahlgren smooth bores, one Dahlgren smoothbore and a 12-pounder howitzer. The USS St Louis was a City class ironclad built in 1861 at Carondelet, Missouri. She was armed with three 8-inch smoothbores, four 42-pounder rifles, six 32-pounder rifles and one 12-pounder rifle at the time of her service at Lucas Bend. Both ships were sent to Cairo, Illinois, early in the Civil War as part of troop transports moving the army into Tennessee. Illinois, a Union state which contributed 250,000 men to the Union Army, a figure surpassed by only New York, Pennsylvania, and Ohio, was a key theater. Cairo, at the confluence between the Mississippi and Ohio rivers, was a key supply point and headquarters for Flag Officer Andrew Hull Foote and General Ulysses S. Grant. It was defended by Fort Defiance. The complex river network provided routes for the Union gunboats into the heart of the Confederate forces; however the water levels – particularly in the Tennessee River – were often not sufficient for gunboats to pass.


b