The correct answer that would best complete the given statement above would be option D. After Germany’s unification in 1871, industrialization accelerated and constructed vast networks of railroads. Hope this is the answer that you are looking for. Thanks for posting your question.
The correct answer is alternative 4 (D): "<em>Constructed vast networks of railroads."</em>
After its unification, German Industry grew strong, but it didn't surpass the US in steel production, and industrialization continued all over the land. Besides, it wasn't hard to find workers for industrial jobs.
The construction of railroads is both a result of and a factor in the industrial growth of Germany.
