I want to know the answer to the following question:
Who grouped 23 unpublished pieces and published them as Opp. 66-73 in 1855?
All the background I'm provided with is that "At the request of the composer's mother and sisters, however, his musical executor Julian Fontana selected 23 unpublished piano pieces and grouped them into eight further opus numbers (Opp.". Is that enough to answer the question?
Answer: yes