What is the unit digit in the product (3^65 x 6^59 x 7^71)?  Options:
A) 4 B) 8 C) 6 D) 2 E) 1
Unit digit in 3^4 = 1 Unit digit in (3^4)16 = 1   Unit digit in 3^65 = Unit digit in [ (3^4)16 x 3 ] = (1 x 3) = 3   Unit digit in 6^59 = 6   Unit digit in 7^4 ==&gt; Unit digit in (7^4)17 is 1.   Unit digit in 7^71 = Unit digit in [(7^4)17 x 7^3] = (1 x 3) = 3.   Required digit = Unit digit in (3 x 6 x 3) = 4.   4nswer 4)4.
<result>A</result>
What is the unit digit in the product (3^65 x 6^59 x 7^71)?