6. Use the digits $0, 1, 2, 3, 4, 5, 6, 7$ to form a 4-digit even number without repeating any digit, and arrange these numbers in ascending order. The 86th number is ( ).
A. 2064
B. 2056
C. 2054
D. 2062
6. C

Even numbers starting with 1 are $4 \times 5 \times 4 \times 1=80$, so the 86th number is the 6th even number starting with 2. It is 2054.