3. (10 points) In a seven-digit integer, any three consecutive digits form a three-digit number that is divisible by 11 or 13. The largest seven-digit number is
A. 9981733
B. 9884737
C. 9978137
D. 9871773
【Analysis】First, based on the largest 3-digit number being a multiple of 11 or 13. Then, each time, add one more digit to find the largest multiple.

【Solution】In 7-digit numbers, first analyze the first three digits. The largest multiple of 11 is 990, and the largest multiple of 13 is 988. Since 0 cannot be the leading digit, the 7-digit number cannot contain the digit 0. The second largest multiple of 11 is 979, which is less than 988. Therefore, the first three digits are 988.

The 4th digit, if it is a multiple of 11, the number would be 880. If it is a multiple of 13, the number would be 884. The largest is 884. The 5th digit, if it is a multiple of 11, the number would be 847. If it is a multiple of 13, the number would be 845. The largest is 847. The 6th digit, if it is a multiple of 11, the number would be 473. If it is a multiple of 13, there is no multiple of 13 in the range of 470-479. So it is 473.

The 7th digit, if it is a multiple of 11, it would be 737. If it is a multiple of 13, there is no suitable number.
Therefore, this 7-digit number is 9884737.
So the answer is: $B$.