Concept:To convert a repeating decimal to a fraction, multiply by a power of 10 to shift the repeating part, then subtract to eliminate repetition.Explanation:Let x=0.712=0.7121212…The repeating block "12" has two digits, so multiply by 100:100x=71.2121212…Subtract the original x:100x−x=71.2121212…−0.7121212…This gives 99x=70.5Convert 70.5 to a fraction: 70.5=2141​So x=2141​÷99=2141​×991​=198141​Simplify by dividing numerator and denominator by 3:x=6647​Answer:6647​, which is option A.