When an electric heater is switched on, the current flowing through it (i) is plotted against time (t). Taking into account the variation of resistance with temperature, which of the following best represents the resulting curve?

Once the heater is turned on, it starts to heat and reach a steady state temperature which is much higher than the room temperature. We know with increase in temperature, the resistance of the coil will also increase. With increase in resistance more current is drawn to reach steady state and once the steady state temperature is attained, current being drawn decreases.