The correct answer is B. The telegraph was invented in the 1840s.
The telegraph is a device that allows two or more distant locations to communicate with each other by sending electrical signals over a wire. The first practical telegraph was invented by Samuel F.B. Morse in 1837. Morse’s telegraph used a code of dots and dashes, called Morse code, to represent letters and numbers. The telegraph was a major breakthrough in communication technology, and it revolutionized the way people communicated with each other.
The 1840s was a decade of great technological innovation. In addition to the telegraph, other important inventions from this decade include the steam locomotive, the sewing machine, and the revolver. The 1840s was also a time of great political and social change. The United States annexed Texas in 1845, and the Mexican-American War began in 1846. The 1840s was a decade of great progress and change, and the telegraph was one of the most important inventions of this time.
Option A is incorrect because the telegraph was not invented in the 1810s. The first practical telegraph was invented by Samuel F.B. Morse in 1837.
Option C is incorrect because the telegraph was not invented in the 1870s. The telegraph was invented in the 1840s.
Option D is incorrect because the telegraph was not invented in the 1890s. The telegraph was invented in the 1840s.