Standard air is the air at?

• A. Atmospheric conditions at any specific location
• B. 20¬¨‚àûC and 1 kg/cm¬¨‚⧠and relative humidity 36%
• C. 0¬¨‚àûC and standard atmospheric conditions
• D. 15¬¨‚àûC and 1 kg/cm¬¨‚â§