Which of the following is not true, regarding abutment selection for overdenture  fabrication?
If mild to moderate bone loss is present, change in crown:root ratio can make the tooth suitable as an overdenture abutment.
Abutment should have healthy periodontal tissues
If bone loss is present, teeth should not be selected as overdenture abutments
A circumferential band of attached gingiva should be present
If a tooth has grade III mobility, it should not be selected as overdenture abutment