What is the tens digit of 6^18?	Choose the correct answer.
A) 1	B) 3	C) 5	D) 7	E) 9
The tens digit of 6 in integer power starting from 2 (6^1 has no tens digit) repeats in a pattern of 5: {3, 1, 9, 7, 5}:   The tens digit of 6^2=36 is 3.   The tens digit of 6^3=216 is 1.   The tens digit of 6^4=...96 is 9.   The tens digit of 6^5=...76 is 7.   The tens digit of 6^6=...56 is 5.   The tens digit of 6^7=...36 is 3 again.   etc...   18 has the form 5n+3, so the tens digit of 6^18 is 1.   The answer is 1.
<result>A</result>
What is the tens digit of 6^18?