A circuit consists of an ideal battery of voltage \(\mathcal{E}\), a fixed resistor of resistance \(R\), and a thermistor connected in series, as shown. The thermistor has a negative temperature coefficient, meaning its resistance \(R_{th}\) decreases as its temperature increases. At time \(t = 0\), the thermistor is at room temperature with resistance \(R_{th}(0) = R\). As current flows for \(t > 0\), Joule heating causes the thermistor's temperature to rise until it reaches thermal equilibrium with its surroundings at a steady-state current \(I_{ss}\). Which of the following graphs best represents the current \(I\) in the circuit as a function of time \(t\)?