Viral Infections Are Often More Difficult to Treat Than Other

Viral infections are often more difficult to treat than other types of infections because

A) viruses contain organelles (ribosomes, mitochondria, etc.) that are naturally resistant to antiviral drugs
B) virus particles are much larger in size than other infectious microorganisms such as bacteria
C) viruses penetrate into human cells, and cannot be easily killed without harming the human cell
D) all the above are true
E) none of the above are true