Which element， defined as a child of a element in the web application deployment descriptor， guarantees a servlet will be initialized at the time the application is deployed？（）
- AA. <load-on-startup/>
- B <load-on-startup>1</load-on-startup>
- C <load-on-startup>-1</load-on-startup>
- D <load-on-startup>true</load-on-startup>