B . Spring provides a Dependency Injection container. True. One of the core features of Spring is its powerful Dependency Injection (DI) container, which helps manage the lifecycle and dependencies of the application's components. E. Spring provides abstractions over infrastructure such as persistence and messaging. True. Spring provides a range of abstractions over various infrastructure concerns, such as persistence (with Spring Data and JPA), messaging (with Spring JMS and Spring AMQP), transaction management, and more. These abstractions simplify and unify the way developers interact with these systems.

https://www.baeldung.com/spring-getbean#3-retrieving-bean-by-type

A web slice test is a type of test in Spring Boot that focuses on testing only the web layer of an application, without starting a full server or requiring a real database. To isolate the web layer from other dependencies, such as services or repositories, mocks can be used to simulate their behavior and return predefined responses. To create and inject a mock for an existing bean in the application context, the @MockBean annotation can be used on a field or a parameter in the test class. This annotation will replace any existing bean of the same type with a mock created by Mockito.