12. (12 points) Today is December 21, 2013, and the seven-digit number $\overline{\mathrm{ABCDEFG}}$ exactly satisfies: the five-digit number $\overline{\mathrm{BCDE}}$ formed by the first five digits is a multiple of 2013, and the five-digit number $\overline{\mathrm{DEFG}}$ formed by the last five digits is a multiple of 1221. Then the minimum value of the four-digit number $\overline{\mathrm{ABFG}}$ is ( )
A. 1034
B. 2021
C. 2815
D. 3036
is a multiple greater than 10. $2013 \times \overline{\pi n}=2000 \times \overline{\pi n}+13 \times \overline{\pi n}$, and it is found that $\overline{\mathrm{CDE}}$ is a multiple of 13.
$\overline{\mathrm{CDEFG}}$ is a five-digit number and is a multiple of 1221, starting enumeration from 10 times.
$1221 \times 10=12210$, the first three digits 122 are not a multiple of 13,
$1221 \times 11=13431$, the first three digits 134 are not a multiple of 13,
$1221 \times 12=14652$, the first three digits 146 are not a multiple of 13,
$1221 \times 13=15873$, the first three digits 158 are not a multiple of 13,
$1221 \times 14=17094$, the first three digits 179 are not a multiple of 13,
$1221 \times 15=18315$, the first three digits 183 are not a multiple of 13,
$1221 \times 16=19536$, the first three digits $195 \div 13=15$, satisfying the condition. $2013 \times 15=30195, \overline{\mathrm{ABFG}}=3036$. Therefore, the answer is: D.