The Answer is a I just took the test, and it didn't eliminate the need of a railroad, nor was it constructed on a land with few plants or animals, it was in a jungle like environment.
ANSWER IS A
First of all, the Spanish (along with the rest of the large European countries at the time) had guns and other military technology. With the advantage of having gunpowder, the Spanish were able to relatively easily conquer the indigenous peoples in the Americas. Another point is the Spanish military training; the American civilizations had no military training that matched the strict codes of the European countries, so the precision of the Spanish helped them conquer.
Answer:
Harding from 1921 to 1923. Secretary of the Interior Albert Bacon Fall had leased Navy petroleum reserves at Teapot Dome in Wyoming, as well as two locations in California, to private oil companies at low rates without competitive bidding. The leases were the subject of a seminal investigation by Senator Thomas J.