3. When do you replace the existing software with the upgrade software? A) During the boot, the boot software immediately starts downloading the upgrade software (if available) from a remote server into an assigned upgrade region in the non-volatile memory (such as EEPROM), then it jumps to the start section in RAM. B) After boot software exits, when the main software is fully up and running, it may periodically check for new update on a remote server. If update is available, it downloads and writes it to an assigned upgrade region in the non-volatile memory (such as EEPROM). C) During the boot, the boot software immediately starts downloading the upgrade software (if available) from a remote server into the RAM and when complete it jumps to the start section in RAM. D) After boot software loads the factory default software image into the RAM, it starts downloading the upgrade software if available from a remote server to an assigned upgrade region in the non-volatile memory (such as EEPROM).