Using the Modern Rules of Validity, Find the Unstated Premise

Multiple Choice

Using the modern rules of validity, find the unstated premise of the following enthymeme. All classrooms on our campus have chalkboards.
_______________________________________
All rooms in Gustav Hall have chalkboards.

A) Some rooms that have chalkboards are rooms in Gustav Hall.
B) Some rooms in Gustav Hall have chalkboards.
C) All classrooms on our campus are rooms in Gustav Hall.
D) All rooms in Gustav Hall are classrooms on our campus.
E) Some rooms that have chalkboards are rooms on our campus.