Final answer:
The question cannot be answered with the information provided as the volume of the flask and the specific gas constant or molar mass of air is missing, thus the answer is a) Not enough information.
Step-by-step explanation:
The student's original question "Assuming the pressure is 758.4 torr and the temperature is 24.6 °C, calculate the mass of dry air in the flask." cannot be answered with the information provided because the volume of the flask and the specific gas constant or the molar mass of the air would be necessary to apply the ideal gas law (PV=nRT) or a derived formula for mass calculation. Therefore, the correct response is a) Not enough information.