What is the primary difference between avirus and a worm?

• A. A worm has the ability to self-propagate from an infected user’s computer to other computers
• B. A worm is usually written by a cracker : Script bunnies do not have the skills to develop worm program
• C. A virus is very harmful to the computers it infects; a worm is not a serious a problem
• D. Anti-virus software is effective in fighting viruses but not worms
• E. None of these