The correct answer is A) Child mortality rates increased significantly.
During the early phases of industrialization, many children faced harsh living and working conditions, leading to increased child mortality rates. Factors such as poor sanitation, cramped living conditions, and long working hours in factories contributed to high rates of disease and death among children. It wasn't until later in the industrial period, with improvements in public health, sanitation, and access to medical care, that child mortality rates began to decline significantly.