Answer:
A
Step-by-step explanation:
Given the exponential function
f(t) = 228[tex](0.975)^{t}[/tex] ← where t is time in years
Substitute t = 20 into f(t), that is
f(20) = 228 × [tex](0.975)^{20}[/tex] = 228 × 0.60268.... ≈ 137 → A