Discrepancies of quantity occur because:
选项：

A:
A: some consumers have more money than others;
B:
B: individual producers tend to specialize, while individual consumers want a broad assortment of product;
C:
C: consumers demand more product variety than producers can make;
D:
D: to obtain economies of scale, individual producers often make larger quantities of products than individual consumers normally want to buy;
E:
E: there are many more consumer than producers.