The Essential Difference Between a Change in the Quantity Demanded

The essential difference between a change in the quantity demanded and a change in demand is

A) the first is a shift of the curve,while the second is a movement along the curve.
B) nothing;both are caused by a change in price.
C) the first is a movement along the curve,while the second is a shift of the curve.
D) the first is caused by changes in income,while the second is caused by a change in price.
E) nothing;both are caused by a change in incomE.