\(a\) and \(b\) are positive integers less than or equal to \(9.\) If \(a\) and \(b\) are assembled into the six-digit

[Vincen]

\(a\) and \(b\) are positive integers less than or equal to \(9.\) If \(a\) and \(b\) are assembled into the six-digit number \(ababab,\) which of the following must be a factor of \(ababab?\)

(A) 3
(B) 4
(C) 5
(D) 6
(E) none of the above

Answer: A

Source: Manhattan GMAT