Option 1: The pressure exerted by the blood in blood capillaries is slightly less than the atmospheric pressure. This option is incorrect. If the pressure in the blood capillaries was less than the atmospheric pressure, the blood would not be able to push out of the capillaries and cause bleeding.

Option 2: The pressure exerted by the blood in blood capillaries is more than the atmospheric pressure. This option is correct. When a person is at a great height above sea level, the atmospheric pressure decreases. However, the pressure in the blood capillaries remains relatively constant. This results in a higher pressure in the capillaries compared to the lower atmospheric pressure, leading to bleeding from the nose.

Option 3: There is no difference in the internal and external pressures on the walls of the cells and blood capillaries. This option is incorrect. As mentioned above, the atmospheric pressure decreases at higher altitudes. Therefore, there is a difference in pressure between the internal blood capillaries and the external atmosphere.

Option 4: Blood capillaries in the nose can absorb less oxygen at greater height, so it bursts. This option is incorrect. The bursting of blood capillaries is not related to the absorption of oxygen. It