ANS:A - 100

Wet bulb and dry bulb temperatures become identical at 100 percent saturation curve. At 100 percent saturation curve, the air is fully saturated with water vapor, meaning it cannot hold any more moisture at the given temperature and pressure. In this condition, the wet bulb temperature, which represents the temperature measured with a thermometer covered with a wet cloth, is equal to the dry bulb temperature, which represents the temperature measured with a standard thermometer. Therefore, at 100 percent saturation curve, the wet bulb and dry bulb temperatures are identical.