Which function is shown in the graph below?

On a coordinate plane, an exponential function shows decay. It rapidly decreases into quadrant 1 and approaches y = 1 in quadrant 1.
y = (one-half) Superscript x + 3 Baseline minus 1
y = (one-half) Superscript x minus 3 Baseline + 1
y = (one-half) Superscript x minus 1 Baseline + 3
y = (one-half) Superscript x + 1 Baseline minus 3