Answer:
"He initially refrained from committing ground forces after being advised that North Koreans could be stopped solely by America's superior air and naval power."
Explanation:
World War I killed more people (9 million combatants and 5 million civilians) and cost more money ($186 billion in direct costs and another $151 billion in indirect costs) than any previous war in history
I hope that this helps you
Should be the second answer (b)