Final answer:
Germany was the country that produced the most steel in the early twentieth century, surpassing Great Britain by the 1890s. The correct option is a.
Step-by-step explanation:
The country that produced the most steel in the early twentieth century was Germany. By following the British model, importing technology, and learning from Britain's advancements in industry, Germany experienced a significant increase in steel production, especially after its unification in 1871.
This surge in industrial capacity allowed Germany to surpass Great Britain in steel production by the 1890s, making them an emerging military and imperial powerhouse going into the 20th century.
Furthermore, by the turn of the century, the United States also saw a dramatic increase in steel production, eventually becoming the top producer in the world by 1910. The correct option is a.