DOCS-246 punctuation edit

Author: Bob Grabar

source/tutorial/deploy-geographically-distributed-replica-set.txt

@@ -29,13 +29,13 @@ Requirements
 
 For a three-member replica set you need two instances in a
 primary facility (hereafter, "Site A") and one member in a secondary
-facility (hereafter, "Site B"). Site A should be the same facility or
+facility (hereafter, "Site B".) Site A should be the same facility or
 very close to your primary application infrastructure
 (i.e. application servers, caching layer, users, etc.)
 
 For a four-member replica set you need two members in Site A,
 two members in Site B (or one member in Site B and one member in Site
-C), and a single :term:`arbiter` in Site A.
+C,) and a single :term:`arbiter` in Site A.
 
 For replica sets with additional members in the secondary facility or with
 multiple secondary facilities, the requirements are the same as above but with the