Why is cell-mediated immunity (in addition to humoral immunity)needed to defend the body against invading pathogens?

A)Humoral immunity is ineffective against antibodies.
B)Antibodies are not effective against pathogens that are present inside cells.
C)Antibodies are not effective against pathogens that are present outside cells.
D)If used too often, antibodies can attack red blood cells.
E)Antibodies are typically ineffective against bacteria, while they work well against viruses.