gmat数学题Q15:If n is a positive integer and r is the remainder

gmat数学题
Q15:
If n is a positive integer and r is the remainder when (n – 1)(n + 1) is divided by 24,what is the value of
(1)x05 2 is not a factor of n.
(2)x05 3 is not a factor of n.
x05x05
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.