Answer:
Option C: We think how great had been our bliss, If Heaven had but assigned us / To live and die in scenes like this, With some we ’ve left behind us!
Step-by-step explanation:
In this line, "We think how great had been our bliss", the author sounds grateful to the memories between the characters. The author goes to past and explains his fantasies about being in heaven and to live and die in the scenarios that the character sees while travelling on his ship. Those expressions were better explained in these lines "If Heaven had but assigned us" and "To live and die in scenes like this". These are the lines that best support the idea that the speaker still finds comfort in those he's left behind.