What is the unit digit in the expansion of (57242)^9x7x5x3x1 ?
A
2
B
4
C
6
D
8
Correct Answer: Option A
Explanation
1. **Focus on the Unit Digit**: The question asks for the unit digit of $(57242)^{9 \times 7 \times 5 \times 3 \times 1}$. As per 'Unit Digit Analysis' [41], we only care about the last digit of the base. So, the problem simplifies to fi