It is insufficient; it only explains how one part of the community--library employees--will be affected. This is the correct option.
The claim refers to the entire community not to the library staff. The community may be made up of the library employees and more people. The evidence just tells that the library staff will be reduced , so there will be less people working for the libary. The people who will be fired will become unemployed. This is an effect. The evidence does not say anything about what will happen to other members of the community such as readers, families , school staff, local book publishers or local book sellers, for example.
These options are not right:
-It is sufficient; it fully explains how the cuts will affect community members. ( It just mentions what will happen to a group of commnunity members: the library staff.)
-It is sufficient; it explains that the staff will have less time to help community members. ( The number of staff members will be reduced , so there will be less employees. The evidence sets the focus on this ,not on a reduction of working hours).
-It is insufficient; library employees are not community members, so the impact on the community is not explained. ( Although the library employees may not be community members , the evidence has set the focus on the reduction of library staff. The evidence does not make any connection bewteen the reduction of staff and the effect on the community. The connection is between the budget cuts and the shortage of library jobs).