What is the atmospheric pressure at sea level?

The atmospheric pressure at sea level is commonly accepted to be approximately 1.01 bar. This unit of measurement provides a clear representation of the pressure exerted by the weight of the atmosphere at sea level.

In the context of different pressure units, 1 bar is equivalent to 100 kilopascals (KPa), which aligns well with the commonly used value of 101.3 KPa for atmospheric pressure at sea level, which rounds to 1.01 bar. This makes option C a typical reference point for atmospheric pressure, facilitating calculations in various scientific and engineering contexts.

While other choices present different pressure values, they either reflect alternate conditions or use different scales that are not standard for defining atmospheric pressure at sea level, making option C the most correct and relevant answer.