An area of a page that includes content from a second template page. Template pages are
Visualforce pages that include one or more <apex:insert> components. The <apex:composition>
component names the associated template, and provides body for the template’s <apex:insert>
components with matching <apex:define> components. Any content outside of an
<apex:composition> component is not rendered.

A.
apex:inputSecret

B.
apex:composition

C.
apex:pageblockSection

D.
apex:lineSeries