The United States agreed to engage in a "Europe First Strategy" with Great Britain because its priority was to help its allies first defeat the Nazis. Following the Nazis successful invasion of France the United States sought to prevent the Nazis from invading Great Britain and instead defeat them first.
B. natives; they knew the most about the land and how to grow crops
Saudi Arabia feared an Iraqi invasion because Iraq invaded nearby Kuwait for its oil and Saudi Arabia. Option A is correct.
Kuwait was reluctant to decrease its oil production and that refusal was considered by Iraq as an act of aggression against it.
Later on, by annexing Kuwait, Iraq took control of 20 percent of the world's oil reserves as well as of a substantial coastline on the Persian Gulf.