The domestic demand ​(​QD) for wheat in the United States is estimated to be
QDD = 1430​ - 55P
where the quantity of wheat is measured in millions of bushels per year. Suppose China also demands U.S. wheat ​(​QDC) and that its demand is given by
QDC = 2100 - 100P
What is the total demand for U.S.​ wheat, assuming the only two sources of demand are domestic and​ Chinese?
The total demand for U.S. wheat is:____.
A. QD = 3530 - 155P for all P.
B. QD = 1430 - 55P for all P.
C. QD = 3530 - 155P for P < or = to $26 and QD = 2100 - 100P for P > $26.
D. QD = 3530 - 155P for P < or = to $21 and QD = 2100 - 100P for P > $21.
E. QD = 3530 - 155P for P < or = to $21 and QD = 1430 - 55P for P > $21.