2. (8 points) For any natural number, define $n i=1 \times 2 \times 3 \times \cdots \times n$. Then the unit digit of the calculation result of $2014 i-3 i$ is ( )
A. 2
B. 4
C. 6
D. 8
【Solution】Solution: According to the new definition: $n i=1 \times 2 \times 3 \times \cdots \times n$, we get:
$$
\begin{array}{l}
2014 i=1 \times 2 \times 3 \times 4 \times 5 \times \cdots \times 2013 \times 2014 \\
=1 \times 3 \times 4 \times 6 \times 7 \times 8 \times \cdots \times 2013 \times 2014 \times 10
\end{array}
$$

Therefore, $1 \times 3 \times 4 \times 6 \times 7 \times 8 \times \cdots \times 2013 \times 2014 \times 10$ is a multiple of 10, so the unit digit of $2014 i$ is 0;
$$
3 i=1 \times 2 \times 3=6
$$

Therefore, the unit digit of $2014 i-3 i$ is: $10-6=4$. Hence, the answer is: $B$.