The correct answer is A. ±0.2.
The internal pressure coefficient is a factor that is used to calculate the internal pressure on a wall. It is a function of the permeability of the wall, the type of soil, and the depth of the wall. For buildings with large permeability, the internal pressure coefficient is taken as ±0.2. This means that the internal pressure on the wall can be either positive or negative, depending on the specific conditions.
A positive internal pressure coefficient indicates that the soil is pushing against the wall. This can happen if the soil is saturated or if there is a lot of water pressure in the soil. A negative internal pressure coefficient indicates that the soil is pulling away from the wall. This can happen if the soil is dry or if there is a lot of air pressure in the soil.
The internal pressure coefficient is an important factor to consider when designing a building. It is used to calculate the required thickness of the wall and the type of reinforcement that is needed. The internal pressure coefficient is also used to calculate the maximum bending moment and shear force that the wall will experience.
The other options are incorrect because they do not represent the correct value of the internal pressure coefficient for buildings with large permeability.