In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

[Q]: The expansion of what further cemented Houston's emergence as a powerhouse commercial city?, Context: By 1860, Houston had emerged as a commercial and railroad hub for the export of cotton. Railroad spurs from the Texas inland converged in Houston, where they met rail lines to the ports of Galveston and Beaumont. During the American Civil War, Houston served as a headquarters for General John Bankhead Magruder, who used the city as an organization point for the Battle of Galveston. After the Civil War, Houston businessmen initiated efforts to widen the city's extensive system of bayous so the city could accept more commerce between downtown and the nearby port of Galveston. By 1890, Houston was the railroad center of Texas.
[A]: bayous


[Q]: Which has more prestige, the Spring Cup Series or low-tier NASCAR circuits?, Context: In addition to professional team sports, North Carolina has a strong affiliation with NASCAR and stock-car racing, with Charlotte Motor Speedway in Concord hosting two Sprint Cup Series races every year. Charlotte also hosts the NASCAR Hall of Fame, while Concord is the home of several top-flight racing teams, including Hendrick Motorsports, Roush Fenway Racing, Richard Petty Motorsports, Stewart-Haas Racing, and Chip Ganassi Racing. Numerous other tracks around North Carolina host races from low-tier NASCAR circuits as well.
[A]: Sprint Cup Series


[Q]: What is learned from metadata?, Context: Database storage is the container of the physical materialization of a database. It comprises the internal (physical) level in the database architecture. It also contains all the information needed (e.g., metadata, "data about the data", and internal data structures) to reconstruct the conceptual level and external level from the internal level when needed. Putting data into permanent storage is generally the responsibility of the database engine a.k.a. "storage engine". Though typically accessed by a DBMS through the underlying operating system (and often utilizing the operating systems' file systems as intermediates for storage layout), storage properties and configuration setting are extremely important for the efficient operation of the DBMS, and thus are closely maintained by database administrators. A DBMS, while in operation, always has its database residing in several types of storage (e.g., memory and external storage). The database data and the additional needed information, possibly in very large amounts, are coded into bits. Data typically reside in the storage in structures that look completely different from the way the data look in the conceptual and external levels, but in ways that attempt to optimize (the best possible) these levels' reconstruction when needed by users and programs, as well as for computing additional types of needed information from the data (e.g., when querying the database).
[A]:
data about the data