Update source/administration/operational-segregation.txt

Author: kstirman

source/administration/operational-segregation.txt

@@ -7,7 +7,7 @@ Location and Operational Segregation in MongoDB Operations and Deployments
 Operational Overview
 --------------------
 
-MongoDB includes a cluster features that allow database administrators
+MongoDB includes a cluster of features that allow database administrators
 and developers to segregate application operations to MongoDB
 deployments by functional or geographical groupings. This capability
 provides "data center awareness," where application operations target