Bunyaviruses that have been reassorted for the M segment have lost their virulence.Which of the following describes the conclusion from this experiment?

A) The envelope proteins are responsible for virulence.
B) The RNA polymerase is responsible for virulence.
C) The non-structural protein is responsible for virulence.
D) The nucleocapsid protein is responsible for virulence.
E) Virulence is not controlled by any of the above.