In semiconductors, the charge carrier density $n$ increases exponentially with temperature:
$$n(T) = n_0 e^{-E_g / (2 k_B T)}$$Since resistivity is inversely proportional to carrier density:
$$\rho = \frac{m}{n e^2 \tau} \implies \rho(T) = \rho_0 e^{E_g / (2 k_B T)}$$As temperature $T$ increases, resistivity $\rho$ decreases rapidly (exponential decay).
Graph 3 correctly represents this non-linear exponential decrease of resistivity with temperature.
अर्धचालकों में तापमान बढ़ने पर सहसंयोजक बंध टूटने से आवेश वाहकों की संख्या $n$ में चरघातांकी रूप से वृद्धि होती है:
$$\rho(T) = \rho_0 e^{E_g / (2 k_B T)}$$