There Were Many Reasons, but the Underlying Issue Behind the Gulf

There were many reasons, but the underlying issue behind the Gulf War was ________.

A) Saddam Hussein's desire to prevent the spread of an Islamic Revolution
B) Saddam Hussein's desire to become the regional superpower
C) Kuwait's desire to separate from Iraq's Basra province
D) Kuwait and Saudi Arabia's insistence that Iraq pay back loans taken out to defeat Iran
E) Kuwait pumping too much oil from the Rumaila oilfield and driving down world oil prices