Answer: A: Module.
Answer analysis: As the core part of the display system, the LED display screen body involves multiple key components. Now, let's analyze the given options one by one to determine which ones belong to the basic modules of the LED display screen body:
A. Module: The module is the basic building block of the LED display screen body. It consists of multiple LED lamp beads (or pixels) and is responsible for displaying images and video content. The module is designed according to certain specifications and sizes, and can be easily spliced into a large-area display screen. Therefore, the module is undoubtedly one of the basic modules of the LED display screen body.
B. Receiving card: Although the receiving card (or control card, receiving box, etc.) plays an important role in the LED display system, it is mainly responsible for receiving signals from the video processor and converting them into a signal format that the module can recognize. However, the receiving card does not directly constitute a part of the screen body, but is an interface device located between the screen body and the control system. Therefore, the receiving card does not belong to the basic module of the LED display screen body.
C. Switching power supply: The switching power supply provides a stable power supply for the LED display. It is a key component in the display system, but it is also not a basic module of the screen body. The switching power supply is usually installed on the back or near the display screen and connected to the modules and other components on the screen body through cables.
D. Video processor: The video processor is one of the core devices in the LED display system. It is responsible for processing and converting the input video signal to meet the display requirements of the display screen. However, the video processor is also not a basic module of the screen body, but is located at the front end of the display system and connected to control devices such as receiving cards.
In summary, the basic modules of the LED display screen body mainly include modules. These modules are spliced and combined to form a large-area display screen for displaying various images and video content.
Therefore, the correct answer is A: module.