For a rational number to generate a repeating decimal, the correct statement is:
The denominator must not evenly divide any power of 10.
This means that if a rational number is expressed in its simplest form as \( \frac{p}{q} \), where \( p \) is the numerator and \( q \) is the denominator, then \( q \) must contain prime factors other than 2 and 5 for the decimal representation to be repeating. If \( q \) only contains the prime factors 2 and 5, the decimal representation will terminate.