Which graph represents exponential decay?


On a coordinate plane, a straight line has a negative slope.


On a coordinate plane, a curve approaches y = 0 in quadrant 2 and curves up in quadrant 1.


On a coordinate plane, a straight line has a positive slope.


On a coordinate plane, a curve approaches y = 0 in quadrant 1 and curves up in quadrant 2.


edit - answer is D