The function of the nucleocapsid proteins of measles virus is to?

Measles virus is an RNA-containing human virus that is membrane bound. The nucleocapsid proteins are arranged in a helical symmetry inside the viral membrane. Therefore first and second options are not correct. Last option becomes the best answer since third option does not provide a function for the nucleocapsid protein. Also Know: Measles virus: Measles virus is an enveloped negative-sense, single-stranded RNA virus which has hemagglutinin and fusion glycoproteins. The receptor for measles virus is CD46 (membrane cofactor protein), a regulator of complement activation. T and B lymphocytes are infected by measles virus. Incubation period is 7 to 18 days. Koplik's spots appear on mucous membranes. Rash spreads from head to trunk and extremities. Rapid diagnosis is possible by immunofluorescence or PCR. Live, attenuated measles vaccine is available and is highly immunogenic. It is most commonly administered as MMRV. Ref: Ray C.G., Ryan K.J. (2010). Chapter 10. Mumps Virus, Measles, Rubella, and Other Childhood Exanthems. In C.G. Ray, K.J. Ryan (Eds), Sherris Medical Microbiology, 5e.