Final answer:
The correct adapter for converting digital to analog video is the HDMI to VGA adapter, and for analog to digital video, it is the VGA to HDMI adapter. USB to HDMI and HDMI to USB adapters are not used for such conversions.
Step-by-step explanation:
If you need to convert between digital and analog video, the type of adapter required would depend on the direction of the conversion. For converting a digital signal (typically HDMI) to an analog signal (VGA), you would need an HDMI to VGA adapter. This adapter would allow you to connect a modern computer or video output device that outputs digital video through an HDMI port to an older monitor or projector that only supports the analog VGA input.
Conversely, if you need to convert from an analog VGA signal to a digital HDMI signal, you would use a VGA to HDMI adapter. This conversion is commonly required when connecting older computers or video sources that only provide a VGA output to newer displays that accept HDMI input.
Therefore, the correct answer is 1) HDMI to VGA adapter if the conversion is from digital to analog, and 2) VGA to HDMI adapter if the conversion is from analog to digital. USB to HDMI and HDMI to USB adapters are for different purposes and not typically used for converting the video signals between analog and digital formats.