I want to know the answer to the following question:
Which opera director did Frédéric see works of during his stay in Berlin?
All the background I'm provided with is that "In September 1828 Chopin, while still a student, visited Berlin with a family friend, zoologist Feliks Jarocki, enjoying operas directed by Gaspare Spontini and attending concerts by Carl Friedrich Zelter, Felix Mendelssohn and other celebrities.". Is that enough to answer the question?
Answer: yes