Question: How are JDK Dynamic proxies and CGLIB proxies used in Spring?

1. JDK Dynamic proxy can proxy only interface, so it is used if the target implements at least one interface. A CGLIB proxy can create a proxy by subclassing and is used if the target does not implement an interface.
2. Only JDK Dynamic proxies are used in the Spring Bean Lifecycle. CGLIB proxies are used only for integrating with other frameworks.
3. Only CGLIB proxies are used in the Spring Bean Lifecycle. JDK Dynamic proxies are used only for integrating with other frameworks.
4. JDK Dynamic proxy can only using an abstract class extended by a target. A CGLIB proxy can create a proxy through bytecode interweaving and is used if the target does not extend an abstract class.

Answer: The correct answer of the above question is Option A:JDK Dynamic proxy can proxy only interface, so it is used if the target implements at least one interface. A CGLIB proxy can create a proxy by subclassing and is used if the target does not implement an interface.