Answer: Option A.
Bacteria are larger than viruses but can be killed by vaccines.
Explanation:
Bacteria and viruses are single celled microorganisms that can be seen with the aid of electron microscope. Both bacteria and viruses have complete genetic code of DNA and RNA. Bacteria are over 1000 times larger than viruses.
Vaccines are biological substances that boost the immune system to destroy infectious diseases. Vaccines are used to kill bacteria by destroying them or stoping their growth.