Patients with Severe Bacterial Sepsis Who Develop a Fever Have

Patients with severe bacterial sepsis who develop a fever have higher survival rates than those who do not develop a fever. Does this observation provide causative evidence for the beneficial role of fever in fighting infections?

A) Yes; patients who develop a fever will have a higher mean fitness.
B) Yes; developing a fever is correlated with a strong immune system.
C) No; the disease in patients without fever may have been too severe to allow the body to develop a fever.
D) No; fever has been shown by other studies to be inconsequential in fighting infections.