Answer: All of the options provided (a. embryonated eggs, b. living animals, c. cell cultures, d. continuous cell lines such as HeLa cells) can be used to grow and study viruses. However, if we are looking for the most versatile and widely used method, especially in laboratory settings, option c. cell cultures, is often the preferred choice. Cell cultures provide a controlled environment for virus growth and allow researchers to study virus-host interactions under controlled conditions. Continuous cell lines such as HeLa cells are commonly used in cell culture studies.
