What is the last digit in the product (3^65 x 6^59 x 7^71) Choose the correct option:
A) 5
B) 6
C) 4
D) 8
E) 9

Rationale: explanation : unit digit in 34 = 1 unit digit in ( 34 ) 16 = 1 unit digit in 365 = unit digit in [ ( 34 ) 16 x 3 ] = ( 1 x 3 ) = 3 unit digit in 659 = 6 unit digit in 74 unit digit in ( 74 ) 17 is 1 . unit digit in 771 = unit digit in [ ( 74 ) 17 x 73 ] = ( 1 x 3 ) = 3 required digit = unit digit in ( 3 x 6 x 3 ) = 4 . answer is c
Answer: C