Final answer:
Upton Sinclair's exposure of unsanitary conditions in the meatpacking industry through his novel 'The Jungle' led to federal legislation that protected public health and consumer rights. Hence, the correct answer is option (B).
Step-by-step explanation:
The work of Upton Sinclair led to changes that protected society by exposing unsanitary meatpacking practices. His influential novel, The Jungle, vividly depicted the appalling conditions in the Chicago meatpacking industry. Upon its publication and widespread impact, President Theodore Roosevelt was compelled to act, leading to the enactment of the Meat Inspection Act and the Pure Food and Drug Act in 1906.
These laws established federal inspections of meat and required clear labeling of food and medicinal products, laying the foundation for what would become the U.S. Food and Drug Administration (FDA).