How is the structure of an RNA phage virion different from the structure of the virion of many dsDNA phages?

A) They have much shorter tails than the DNA phages.
B) The heads do not use icosahedral symmetry.
C) The icosahedral head has a very large triangulation number.
D) They are solely composed of a helical nucleocapsid.
E) They lack the tail structure used to inject the genome into the host cell.