GWD管卫东GMAT 第7套题 If x is a positive integer,is theremainder 0

GWD管卫东GMAT 第7套题
If x is a positive integer,is theremainder 0 when 3^X + 1 is divided by 10?（X是指数,我电脑表示不出来）
(1) x = 4n + 2,where n is apositive integer.
(2) x> 4
A.Statement (1) ALONE is sufficient,but statement (2) alone isnot sufficient.
B.Statement (2) ALONE issufficient,but statement (1) alone is not sufficient.
C.BOTH statements TOGETHERare sufficient,but NEITHER statement ALONE is sufficient.
D.EACH statement ALONE issufficient.
E.Statements (1) and (2)TOGETHER are NOT sufficient.
想不通啊