Which command correctly configures this setup?

You are logged into a router and have navigated to the [edit routing-options] level of the hierarchy.
You have been asked to define an aggregate route for 172.30/16.
Which command correctly configures this setup?

A.
set summary route 172.30/16

B.
set aggregate route 172.30/16

C.
set route aggregate 172.30/16

D.
set route summary 172.30/16

Explanation: