Virus lacking hemagglutinin and neuraminidase but having membrane fusion protein is:

Ans. is 'a' i.e., RSVThe viral envelope contains a surface glycoprotein G, by which it is attached to the cell surface of the host cells. It contains F protein but lacks both H and N proteins. The F protein induces the fusion of the infected cells with adjoining cells, resulting in the formation of large multinucleated syncytia, from which the virus derives its name.