If n is the greatest positive integer for which 4^n is a factor of 8!, then n =?  Pick one:
A) 2  B) 4  C) 6  D) 8  E) 10
8! = 40320   E. 4^10 = 1048576 (40320/1048576) - this is not a factor of 8!   D. 4^8 = 65536 (40320/65536) - this is not a factor of 8!   C. 4^6 = 4096 (40320/4096) - this is not a factor of 8!   B. 4^4 = 256 (40320/256) - this is not a factor of 8!   A. 4^2 = 16 (40320/16) - this is a factor of 8!
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If n is the greatest positive integer for which 4^n is a factor of 8!, then n =?