Read the following passage and answer the questions that follow

Read the following passage and answer the questions that follow. Thomas Alva Edison was born in Ohio in 1847. As a child, he received less than a year of formal schooling, but was educated at home. His parents allowed him to set up a laboratory in their basement and his mother gave him books about chemistry and electronics. Edison credits his mother as being ‘the making’ of him. In 1878, Thomas Edison began serious research into developing a practical incandescent lamp and on October 14, 1878, Edison filed his first patent application for “Improvement in Electric Lights”. In 1879, he created a successful incandescent light bulb. This was his hardest project – from 1877 to 1880, Edison and his assistants tried around 3000 experiments to perfect their light bulb design. By the end of 1880, Edison had produced a bulb that lasted 1500 hours. This discovery marked the beginning of commercially manufactured light bulbs and in 1880, Thomas Edison’s company; Edison Electric Light Company began marketing its new product. Question: What does the word “its” in the last sentence refer to? A. Thomas Edison’s company B. Thomas Edison’s invention C. Thomas Edison’s discovery D. Thomas Edison’s patent 23 Read the following passage and answer the questions that follow. Thomas Alva Edison was born in Ohio in 1847. As a child, he received less than a year of formal schooling, but was educated at home. His parents allowed him to set up a laboratory in their basement and his mother gave him books about chemistry and electronics. Edison credits his mother as being ‘the making’ of him. In 1878, Thomas Edison began serious research into developing a practical incandescent lamp and on October 14, 1878, Edison filed his first patent application for “Improvement in Electric Lights”. In 1879, he created a successful incandescent light bulb. This was his hardest project – from 1877 to 1880, Edison and his assistants tried around 3000 experiments to perfect their light bulb design. By the end of 1880, Edison had produced a bulb that lasted 1500 hours. This discovery marked the beginning of commercially manufactured light bulbs and in 1880, Thomas Edison’s company; Edison Electric Light Company began marketing its new product.
Question: What is the main idea of the passage?
A. Family of Thomas Edison
B. A brief history of the light bulb
C. The early life of Thomas Edison
D. Thomas Edison's company