In my case, IMO is C
I was confused between A and C. Here is my thinking.
A. The quality of service provided by the Care Hospital will certainly decline over the next few months.
-> 'certainly decline over the next few months.'
We cannot assure that within few months, the quality of service would be declined.
It is possible or not.
B. The training program for nurses will have to be comprehensive so the nurses can undertake all the tasks that only doctors undertook previously.
-> 'This approach(training the nurses) will however, not completely solve the problem.'
B refutes the contents of the passage.
C. If recruiting doctors from other hospitals as visiting doctors were possible, it could potentially help the hospital maintain its high quality of care.
-> correct.
'unless the doctor staff is increased' : C said 'doctor staff is increased.'
D. The declining quality of care at the hospital will reduce its patient intake which will solve the problem on its own.
-> Out of scope
It is hard to know. There is no mention about patient intake.
E. Allowing doctors to spend less time per patient will help the hospital maintain the quality of care.
-> Problem comes from what doctors cannot provide enough time for every patient.