The correct option is
B Adenovirus
A virus can be classified into icosahedral, enveloped and complex or helical based on the structure of a virus. Polyhedral viruses consist of nucleic acid surrounded by a polyhedral or many-sided shell or capsid and usually in the form of an icosahedron. Adenovirus is an example of a polyhedral virus. Adenoviruses are nonenveloped viruses with an icosahedral nucleocapsid which surrounds the double-stranded DNA genome.
So, the correct answer is 'Adenovirus'.