Which of the following is not a recognized etiology of the disease shown below ?

The slide shows clusters of plasma cell., diagnostic of myeloma. Although multiple myeloma has been reported in some cases of first degree relatives and identical twins, no evidence for hereditary passage of disease exists. Radiation (A) has been shown to increase the risk for multiple myeloma. Farmers using herbicides, insecticides, benzene and organic solvents are also reported to have an increased risk for myeloma. HHV-8 (B) is shown to be present in the dendritic cells originating from the bone marrow of myeloma sufferers while chronic untreated HIV (C) is also associated with increased myeloma risk.