Task: Question Answering
Input (English): Question: Suppose you have three identical prisms with congruent equilateral triangles as the end-polygons. Suppose you attach them by the rectangular faces so they are perfectly aligned. There will be some large faces created by two or more co-planar faces of the individual prisms: count each such large face as one. Given that, how many faces does the resultant solid have

 Option A:  4

 Option B:  9

 Option C: 6

 Option D:  10

 Option E:  12
Output (English): Option C