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
Gennifer, a 4 years got her lower 2nd molar extracted due
to caries, the possible Line of treatment is 
Select and explain. 
A. Distal shoe space maintainer, B. Band and loop between primary 1st molar and permanent 1st molar, C. Removable partial denture, D. No active treatment is necessary
A: Distal shoe space maintainer
Answer: A: Distal shoe space maintainer 
Explanation: None