The most accurate answer to how industrial growth affected the distribution of wealth in the United States is:
b. Wealth was concentrated in the hands of a few industrialists.
During the period of industrial growth, particularly in the late 19th and early 20th centuries, there was significant economic expansion, but this also led to a concentration of wealth among a small number of industrial magnates and business leaders, often referred to as "captains of industry" or "robber barons." While some segments of the population did experience improved living standards, the overall wealth distribution became increasingly unequal.