·cornelius vanderbilt · pullman strike · standard gauge · promontory point, utah all of these terms are associated with a) education. b) agriculture. c) labor strife. d) the railroad industry.

The answer in this case would be D, the railroad industry.

Cornelius Vanderbilt was a railroad tycoon, who owned a significant portion of all railroads and cars in the country. The Pullman Strike was when railroad workers refused to use Pullman cars, which was detrimental to business. The promontory point is where lines built by the Union Pacific and Central Pacific met in 1869, which is important as they are parts of the transcontinental railroad. Finally, a standard gauge is a type of track used by the railroads.

A bit wordy but it tells you why they all relate to railroads :)

The answer is D because Vanderbilt has a railroad industry