Final answer:
Without specific conditions (temperature, altitude, etc.), the pressure of air at steady state cannot be determined from the options provided; standard atmospheric pressure at sea level is 101.325 kPa.
Step-by-step explanation:
The question pertains to the pressure of air at a steady state. To determine the atmospheric pressure of air at a steady state without additional context or specifics (such as temperature and altitude), we cannot provide a precise value. Under standard conditions—which means at sea level and at a temperature of 0 °C—the atmospheric pressure is defined as 101.325 kPa or 1 atmosphere (atm). However, the actual pressure can vary depending on many factors. The values such as 200 kPa or 280 kPa can occur under specific conditions but do not represent standard atmospheric pressure. Thus, without additional information to specify conditions, the pressure of air at steady state cannot be determined from the options provided.