To solve this problem, we need to understand how temperature affects a p-n junction diode.$\\$A p-n junction diode is a semiconductor device that allows current to flow in one direction.$\\$The V-I characteristics of a diode describe the relationship between the voltage across the diode$\\$and the current flowing through it. These characteristics are affected by temperature changes.$\\$Let's analyze the options:$\\$• Option 1: "does not affect resistance of p-n junction"$\\$This is incorrect because temperature affects the intrinsic carrier concentration,$\\$which in turn affects the resistance of the diode.$\\$• Option 2: "affects only forward resistance"$\\$This is incorrect because temperature affects both forward and reverse characteristics.$\\$• Option 3: "affects only reverse resistance"$\\$This is incorrect for the same reason as option 2; temperature affects both forward and reverse characteristics.$\\$• Option 4: "affects the overall V – I characteristics of p-n junction"$\\$This is correct. Temperature changes affect the saturation current,$\\$the forward voltage drop, and the breakdown voltage, thereby affecting the overall V-I characteristics.$\\$Explanation:$\\$• As temperature increases, the intrinsic carrier concentration in the semiconductor increases.$\\$• This leads to an increase in the reverse saturation current, which affects the reverse characteristics.$\\$• The forward voltage drop across the diode decreases with an increase in temperature,$\\$affecting the forward characteristics.$\\$• The breakdown voltage in reverse bias decreases with an increase in temperature.$\\$Therefore, the correct answer is Option 4: "affects the overall V – I characteristics of p-n junction."$\\$