咸宁路站
桃花潭站
Please solve the multiple choice problem and put your answer (one of ABCD) in one "\boxed{}". According to the subway map, how many intermediate stops are there between 咸宁路站 and 桃花潭站 (except for this two stops)? 
A) 12 
B) 15 
C) 6 
D) 21 
