正解:C
A P-iris lens is a type of DC-iris lens that incorporates feedback to maintain optimal image quality. Unlike a standard DC-iris, which only adjusts based on light levels, a P-iris lens uses a feedback mechanism to optimize the iris position, ensuring consistent image sharpness, depth of field, and optimal contrast. This technology allows for precise control over the iris, which is especially beneficial in varying lighting conditions. According to Axis documentation, P-iris lenses are designed to deliver better performance by continuously adjusting the iris for optimal image quality.