A Leftward Shift of a Consumer's Budget Line to a Position

A leftward shift of a consumer's budget line to a position parallel with the original one could indicate that the:

A) price of one product has decreased in relation to the other.
B) prices of both products have decreased in the same proportion.
C) marginal utilities derived from both products have decreased.
D) consumer's money income has increased but the prices of both products have increased proportionately more.