This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Dental
A pier abutment is: 
Select and explain. 
A. Periodontally weak abutment, B. With an edentulous space on mesial and distal sides of the abutment, C. Edentulous space on one side of the abutment, D. Abutment adjacent to edentulous space
B: With an edentulous space on mesial and distal sides of the abutment
Answer: B: With an edentulous space on mesial and distal sides of the abutment 
Explanation: None