You are presented with the question "Viral envelopes are sometimes made of fats and what?" and the following answer choices: 
- cellulose
 - glucose
 - Energy.
 - protein
 - viral particles
 - Energy
 - food
 - bacteria

Now knowing that some viruses have an envelope of phospholipids and proteins and phospholipids are body fats, too, choose the best answer.


 

    protein     