Which of the Following Best Defines Quantity Demanded of a Good

Which of the following best defines quantity demanded of a good?

A) The amount an individual purchases at the good's current price.
B) The amount an individual purchases at his or her current income.
C) The amount,per time period,that is desired at the most recent price.
D) The amount,per time period,an individual desires to purchase at any given price.
E) The various amounts that all individuals desire at all relevant prices.