Answer:
The use of host machinery and simple structure of viruses make them difficult to develop drugs against them. The characteristic of virus which is not a problem in drug development is
C) They are smaller than the host cells
Explanation:
The smaller size of virus is not creating problems in designing drugs against them, in fact due to their small size, many viruses are used as carriers in nanotechnology for site specific drug delivery and offers great diversity which make them different and better from the synthetic nanocarriers.