On a coordinate plane, an exponential function approaches y = 0 in quadrant 2 and increases into quadrant 1. It goes through (negative 1, 1.5), (0, 3), (1, 6). Which exponential function is represented by the graph?

f(x) = 2(3x)
f(x) = 3(3x)
f(x) = 3(2x)
f(x) = 2(2x)