ANS:C - 1 atmosphere

1 atmosphere is the largest quantum of pressure among the options provided. 1 atmosphere (atm) is defined as the standard atmospheric pressure at sea level and is approximately equal to the pressure exerted by a column of mercury 760 millimeters (mm) in height. It is the largest unit of pressure commonly used in everyday contexts. The other units listed are smaller:

• 1 kg/cm² (kilogram per square centimeter) is a unit of pressure often used in engineering and is approximately equal to 98,066.5 pascals.
• 1 bar is a unit of pressure commonly used in scientific and industrial applications, equal to 100,000 pascals.
• 1 kilopascal (kPa) is a unit of pressure in the metric system, equal to 1,000 pascals.