Detailed Instructions: In this task, you are given a multiple-choice question about healthcare. Answer the question based on your information and classify your answers into '1', '2', '3', and '4'.
Q: Question: The Archaea differ from the bacteria in that:
Options: <1> Their membranes have a single phospholipid layer. <2> They have several chromosomes. <3> Their membranes have glycerol ethers. <4> They are not susceptible to viral infection. <5> They do not have a cell wall.
A:
3