What is the unit digit in 7^105?  Choose the most appropriate option.
A) 1 B) 5 C) 7 D) 9 E) None of them
Unit digit in 7^105= Unit digit in [(7^4)^26 x 7]   But, unit digit in (7^4)^26=1   Therefore, Unit digit in 7^105=(1x7)=7   Answer is 7
<result>C</result>
What is the unit digit in 7^105?