The Average Rate Disappearance of a Between 20 S and 30

The average rate disappearance of A between 20 s and 30 s is mol/s.

A) 5.0 × 10^{- 4}
B) 0.15
C) 1.6 × 10^{- 2}
D) 670
E) 1.5 × 10^{- 3}