A6. On a wheel lock, we can set a 3-digit code. For each of the three positions, we can choose one of the digits from 0 to 9. What is the maximum number of different codes we can set?
(A) 30
(B) 100
(C) 300
(D) $9^{3}$
(E) 1000
A6. In each place, we can choose from ten digits, so we can set up $10 \cdot 10 \cdot 10=$ 1000 different codes.