You are presented with the question "What have similar membranes?" and the following answer choices: 
- PDAs
 - humans
 - viruses
 - crocodiles
 - animals
 - sharks
 - fur seals
 - insects

Now knowing that some viruses have an envelope of phospholipids and proteins and viruses are enveloped by similar membranes, choose the best answer.


 

   viruses      