What is the default behavior for a manual summary route when a component route of the summary disappears?

A.	Regardless of the metric if the component route,the metric of the summary is unchanged in order to keep stability.
B.	If the component route previously had the best composite metric ,the same summary metric is retained for stability.
C.	If the component route previously had the best composite metric ,the metric of the summary changes to the next-best composite metric.
D.	if the component route previously did not have the best composite metric,the summary metric is updated,and updates are sent to peers.