Williams went on: "Obviously Their Majesties will be in the Egyptian Apartment."
Fitz nodded. This was the largest suite of rooms. Its wallpaper had decorative motifs from Egyptian temples.
"Mrs. Jevons suggested which other rooms should be opened up, and I've wrote it down by here."
(Ken Follett, Fall of Giants)
I don’t make out what this phrase ‘which other rooms’ means: 'which' does not seem like a fused relative. And there’s some suspicion that ‘which’ might be the wrong use of ‘whose’ by a character in the novel . What does it mean?