Answer:
C
Explanation:
As we can see from the series, each term is 3 multiplied by the term preceding it.
12=3*4
36=3*12
108=3*36
etc.
This way, we can figure out the next terms (until 7th term):
5th term = 108*3=324
6th term = 324*3=972
7th term = 972*3=2916
Now adding all 7 terms, we get the sum:
4+12+36+108+324+972+2916=4372
Answer choice C is right.