For how many positive integers n \leq 1000 is
\left\lfloor\dfrac{998}{n}\right\rfloor+\left\lfloor\dfrac{999}{n}\right\rfloor+\left\lfloor\dfrac{1000}{n}\right\rfloor
not divisible by 3 ? (Recall that \lfloor x\rfloor is the greatest integer less than or equal to x.)
Answer Choices
A. 22
B. 23
C. 24
D. 25
E. 26