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.