What Underlying Infection Should a Physician Immediately Suspect When Confronted

What underlying infection should a physician immediately suspect when confronted with a patient with confirmed cryptococcal meningoencephalitis, and why?

A) Influenza infection. The 2 viruses are often transmitted together in respiratory droplets.
B) HIV infection. People with normal immune systems generally fend off this fungal infection before it becomes clinically symptomatic.
C) Varicella zoster virus (chicken pox) . During the incubation period for chicken pox, and during its latency, C. neoformans has an increased ability to colonize the respiratory tract.
D) Syphilis. This sexually-transmitted illness depletes CD4+ helper T cells that are necessary to directly attack the fungal infection of C. neoformans.