The pressure inside the cabin of the aircraft flying at an altitude is A. The same as that outside. B. Less than that outside. C. More than that outside. D. Normal atmospheric pressure at sea level.

At cruising altitude the outside air pressure is very low. Aircraft cabins are pressurised to keep the pressure at a safe, comfortable level (roughly equal to the air at 6,000–8,000 ft), which is much higher than the pressure outside. So the cabin pressure is more than that outside.