How would each of the following events affect the international price of oil (in each case ceteris paribus):
(a) The United States gives economic assistance to oil-rich Ukraine in the form of oil-drilling technology;
(b) Iran, in a war against Saudi Arabia, destroys 50 percent of Saudi oil wells;
(c) A U.S. invention uses sea-water to fuel automobiles;
(d) Western European homes are heated solely by solar power; and
(e) The world's population doubles.