Clarify subject

Author: kallimachos

source/tutorial/resync-replica-set-member.txt

@@ -59,8 +59,8 @@ data on the member. For an overview of MongoDB initial sync process, see the
 :doc:`Replica Set Syncing </core/replica-set-sync>` section.
 
 Initial sync operations can impact the other members of the set and
-create additional traffic to the primary. They require another member of the
-set that is accessible and up to date.
+create additional traffic to the primary. The syncing member requires another
+member of the set that is accessible and up to date.
 
 If the instance has no data, you can follow the
 :doc:`/tutorial/expand-replica-set` or