Are these good questions and answers for the text?

Hi teachers,
This is for a listening comprehension exercise. The text is from a CD. (The Elephant Man) Context:
‘Lighthouses have sea all round them, don’t they?’ he said. ‘Nobody could look at me in a lighthouse, so I would be happy there. And blind people can see nothing, so they couldn’t see me, could they?’ ‘But Joseph,’ I said, ‘this is your home. You live here now. You aren’t going to leave the hospital.’
Assuming that we know that 'he' is 'Merrick' and 'I' is the doctor, would the following be suitable questions and answers?
3. Did the doctor agree with Merrick? No, he didn’t. (already corrected by Mister Micawber)

Which one is better, '4a' or '4b'?
4a. How do you know? Because the doctor said, ‘This is your home. You live here now. You aren’t going to leave the hospital.’
4b.What was the doctor’s reason not to allow Merrick to leave the hospital? He told him that the hospital was his house and added that he lived there at that time.
Thanks in advance.