According to the passage, the most important evidence supporting the opinion that viruses are not alive is that they
a) cause disease.
b) contain dna or rna.
c) are much smaller than bacteria.
d) do not have a cellular structure.

D) do not have a cellular structure.

Explanation:

Viruses are known to be acellular  as they do not have cellular structure. they do not have most of the cellular components i.e they dont have

 Plasma membrane

  ribosomes

although viruses consist of nucleic acids, proteins,lipids and carbohydrates but they dont have the ability to perform and function and divide unless they enter any other living host cell. viruses uses the machinery of the living host cell and without the cells viruses are unable to divide.

its the cell wall and the they are unique to plant