An online streaming service that offers TV shows, documentaries, and movies charges an initial fee of $20.25 and an additional monthly membership fee of $3.75. The total cost, N(t), for a member after t months can be expressed with the function N(t) = 3.75t + 20.25. What is the range of the function in the context of the problem?

ℝ
[0, ∞)
[3.75, ∞)
[20.25, ∞)