The correct answer is A) They sold stock in their companies to the public.
The statement that describes a legal means used by the companies that built the transcontinental railroad to finance railroad construction is "They sold stock in their companies to the public.
With the Pacific Railroad Act of 1862, the US government gave the task to construct a transcontinental railroad that connected the East and the West of the United States. The companies were the Union Pacific Railroad and the Central Pacific. It took seven years to connect Sacramento Californi with Omaha, Nebraska. Finally, on May 10, 1869, both lines meet in Promontory, Utah.