Fact 1: Some viruses have an envelope of phospholipids and proteins. Fact 2: Viruses are strange life forms. Given the two facts above, some strange life forms have an envelope of what?

Available choices: a. Chemical energy b. biological diversity c. Something coming from a gland d. layers of fat e. characteristics f. phospholipids and proteins g. Positive charges h. visible energy
The answer is:
f.