Statement A is true; M. W. Beijerinck is credited with coining the term "virus" and developing the concept of a virus as an infectious agent distinct from bacteria. Statement B is true; viruses have a genome made of either DNA or RNA, which can be single-stranded (ss) or double-stranded (ds). Statement D is true; RNA viruses generally have higher mutation rates than DNA viruses due to the lack of proofreading activity in RNA-dependent RNA polymerase. Statement C is false; while single-stranded DNA viruses exist (e.g., Parvoviridae), most DNA viruses are double-stranded (e.g., Herpesviridae, Adenoviridae, Poxviridae).