Which of the following is true about pressure for an ideal gas at -273 degrees Celsius?

Explanation

Absolute zero is minus 273 degrees Celsius, and extrapolating a pressure against temperature graph for a fixed volume of ideal gas back to that point gives zero pressure, since molecular motion reaches its minimum and no collisions occur with the walls. No real gas actually reaches this, because every gas liquefies first, so the value is an extrapolation rather than an observation. It is exactly how the absolute scale is defined.