who developed the steel and oil industries in the united states?\n○ gustav swift and robert kraft\n○ andrew…

who developed the steel and oil industries in the united states?\n○ gustav swift and robert kraft\n○ andrew carnegie and john d. rockefeller\n○ j.p. morgan and nelson rockefeller\n○ dale carnegie and james duke
Answer
Brief Explanations:
To determine who developed the steel and oil industries in the US, we analyze each option:
- Gustav Swift and Robert Kraft: Swift was in meatpacking, Kraft in food, not steel/oil.
- Andrew Carnegie (steel) and John D. Rockefeller (oil): Carnegie dominated steel, Rockefeller dominated oil.
- J.P. Morgan (finance/industrial consolidation) and Nelson Rockefeller (later, not industry development era): Morgan consolidated, but Nelson is not key here.
- Dale Carnegie (self - help, writing) and James Duke (tobacco): Not related to steel/oil.
Answer:
B. Andrew Carnegie and John D. Rockefeller