Rich g85 made IMO a very fundamental error. He/she acknowledged a transmission they did not fully understand. This is never a good idea. As a student pilot RT instructions may come up that may leave you flummoxed. The best thing to do is to fess up immediately. So in this case an appropriate reply would have been;
"do you want me to go around immediately or descend to 450 feet and then go around ?"
However to go around, at any point, for any reason, is always an option and is never wrong. The best answer may have been to initiate an immediate go-around and then ask for clarification safe in the knowledge that he wasn't going around too late.