The correct answer is D. 760 mm of mercury
Step-by-step explanation:
One atmosphere (atm) is a unit used to measure pressure (force applied to an object, gas, substance); this unit represents the regular natural pressure that exists at sea level. Additionally, an atmosphere can be equivalent over other pressure units including pascals as 101325 pascals are equivalent to 1 atm; kilopascals as 101.325 kilopascals are the same that 1 atm and even mercury millimeters (mmHg) as one atmosphere is equal to 760 mmHg. Thus, it can be concluded an atmosphere is equal to "760mm of mercury" because this is the only option in which there is a correct equivalence between the atmosphere unit and other units use to measure pressure.