Final answer:
The risk of death increases by 31% in hospitals where nurses have eight patients compared to four patients each is true. The correct option is a.
Step-by-step explanation:
The researchers have found that the risk of death increases by 31% in hospitals where nurses have eight patients compared to four patients each.
For example, if we consider a hospital where nurses have four patients each, and there are 100 patients in total, then there would be 25 nurses. If we increase the number of patients to eight per nurse, the total number of nurses required would decrease to 12.5, which is not possible. This shows that having eight patients per nurse would mean that nurses are overburdened and unable to provide adequate care, leading to a higher risk of death for patients.
The correct option is a.