Colleen is composing a routine message to a manager. The section of the routine message that is usually short and simple as it is leaving things on a neutral or positive note and not asking for the manager to do something is referred to as the$\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_.$

Question content area bottom

Part $1$

A$.$

body

B$.$

courteous close

C$.$

introduction

D$.$

opening

E$.$

appendix