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
The direct filling gold segments can be compacted: 
Select and explain. 
A. By hand pressure alone, B. By hand pressure combined with a hand mallet, C. By using electromallet, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: The gold segments can be compacted by hand pressure alone, by hand pressure combined with a hand mallet, or by a mechanical device  that is activated by a spring, pneumatic pressure, or electronically (using an electromallet). 
The direction of force application, the amount of applied pressure, and the compaction pattern are critically important factors controlling the quality of the gold restoration.

Ref:Phillip’s Science of Dental Materials ed 12 pg 414