A Shift to the Right in the Demand Curve for Product

A shift to the right in the demand curve for product A can be most reasonably explained by saying that

A) consumer incomes have declined, and consumers now want to buy less of A at each possible price.
B) the price of A has increased and, as a result, consumers want to purchase less of it.
C) consumer preferences have changed in favor of A so that they now want to buy more at each possible price.
D) the price of A has declined and, as a result, consumers want to purchase more of it.