GMAT数学题一道If x is a positive integer, is the remainder 0 when

GMAT数学题一道
If x is a positive integer, is the remainder 0 when (3^x + 1)/10?
(1) x = 3n + 2, where n is a positive integer.
(2) x > 4
A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.
答案是A，为什么呢？希望写出详细步骤，谢谢！
题目中是3^x，就是3的x次方的意思。