A sequence $$\{a_n\}$$ is generated by the rule, $$a_n = a_{n-1} - a_{n-2}$$ for $$n \geq 3$$. Given $$a_1 = 2$$ and $$a_2 = 4$$, then sum of the first 2019 terms of the sequence is given by

A

8

B

2692

C

-2692

D

-8