For all positive integers n less than 2002 , let
a_{n}= \begin{cases}11, \text { if } n \text { is divisible by } 13 \text { and } 14 \\ 13, \text { if } n \text { is divisible by } 14 \text { and } 11 \\ 14, \text { if } n \text { is divisible by } 11 \text { and } 13 \\ 0, \text { otherwise }\end{cases}
Calculate \sum_{n=1}^{2001} a_{n}.
Answer Choices
A. 448
B. 486
C. 1560
D. 2001
E. 2002