For the function $$f(t) = e^{\frac{-t}{r}}$$, the Taylor series approximation for $$t << \tau$$ is

A

$$1 + \frac{t}{\tau}$$

B

$$1 - \frac{t}{2 \tau^2}$$

C

$$1 - \frac{t}{\tau}$$

D

$$1 + t$$