Which of the following improper fractions is equal to the mixed number 12 4 7 ​7 ​ ​4 ​​ ? A 4 8 7 ​7 ​ ​48 ​​ B 4 7 1 2 ​12 ​ ​47 ​​ C 2 3 4 7 ​7 ​ ​234 ​​ D 8 8 7 ​7 ​ ​88 ​​