Final answer:
The correct answer is C) Astor, with John Jacob Astor increasing the family fortune to more than $75 million by 1890.
Step-by-step explanation:
By 1890, the second John Jacob Astor had increased the family fortune to more than $75 million. The correct answer to the question is C) Astor. John Jacob Astor was part of a prominent family known for their wealth generated from real estate and fur trading. It is worth noting, however, that other families mentioned in the options, such as the Rockefellers, Vanderbilts, and Carnegies, also played a significant role in American economic history. John D. Rockefeller, in particular, increased his own family's fortune significantly through the oil industry with his company, Standard Oil.