The last choice, f(x)=1/4(4ˣ⁻⁻¹)-4, is correct.
Substituting our values for x, we have:
f(2) = 1/4(4²⁻¹)-4 = 1/4(4¹) - 4 = 1/4(4) - 4= 1 - 4 = -3
f(3) = 1/4(4³⁻¹)-4 = 1/4(4²) - 4 = 1/4(16) - 4 = 4 - 4 = 0
f(4) = 1/4(4⁴⁻¹)-4 = 1/4(4³) - 4 = 1/4(64) - 4 = 16 - 4 = 12
All of the data points fit.