Which expressions describe the end behaviors of the function, f(x)=(3.25)^x+6, modeled by the graph?

A: As x decreases without bound, f(x) increases without bond
B: As x increases without bound, f(x) increases without bond
C: As x decreases without bound, f(x) approaches the line y = 6
D: As x increases without bound, f(x) approaches the line y = 6