A user is attempting to open on a mobile phone a HD video that is...

Comprehensive and Detailed Explanation From Exact Extract:

3G networks generally do not provide the bandwidth required for seamless HD video streaming. With only two signal bars and a 3G connection, the mobile device likely cannot maintain the necessary data throughput, resulting in timeouts or buffering failures. This is a classic symptom of insufficient network speed or signal strength.

A. Lack of Wi-Fi may contribute, but the root cause is the low mobile bandwidth, not the Wi-Fi state.

B. A website subscription lapse would return an account error, not a timeout.

D. Full device storage can affect downloads but not streaming from the internet.