Use the information to answer the question that follows. During the 1840s, the population of towns and cities of 8,000 or more increased by 90%. Only five families lived in the town of Lowell, Massachusetts, in 1821, for instance. By 1836, however, over 10,000 people lived there, and Lowell had become the second largest town in the state in 1850, when the population reached 33,000. What BEST explains this population trend? O A. Industrial factories attracted large numbers of workers. O B. Plantations grew in size due to the rising demand for cotton. DC. Port cities prospered as lower tariffs led to an increase in trade. O D. Boom towns developed as people migrated during the gold rush.

Use the information to answer the question that follows. During the 1840s, the population of towns and cities of 8,000 or more increased by 90%. Only five families lived in the town of Lowell, Massachusetts, in 1821, for instance. By 1836, however, over 10,000 people lived there, and Lowell had become the second largest town in the state in 1850, when the population reached 33,000. What BEST explains this population trend? O A. Industrial factories attracted large numbers of workers. O B. Plantations grew in size due to the rising demand for cotton. DC. Port cities prospered as lower tariffs led to an increase in trade. O D. Boom towns developed as people migrated during the gold rush.