Answer:
636 mm Hg
Explanation:
The pressure in the gas container is equal to the atmospheric pressure minus the height of mercury:
Atmospheric pressure = 722 torr = 722 mm Hg
Height = 8.60 cm = 86 mm Hg
Pressure = 722 - 86 = 636 mm Hg
So none of the given options is correct, the correct answer is 636 mm Hg.