Final answer:
The Second Industrial Revolution was driven by innovations in steel production, the extraction of oil from coal, and the development of the internal combustion engine.
Step-by-step explanation:
The Second Industrial Revolution was brought about by several factors, but the choices given in the question help to identify some key elements. Option A, innovators developing a process to produce steel inexpensively, was a significant development that allowed for the mass production of steel, which fueled the growth of industries such as railroads and construction. Option D, scientists inventing a process for extracting oil from coal, also played a crucial role in the Second Industrial Revolution by providing an abundant and cheap source of energy. Finally, option B, engineers building the first internal combustion engine, marked a major technological advancement that revolutionized transportation and manufacturing.
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