Consider the following reaction : <br> $A \to products$ <br> This reaction is completed in 100 minutes. The rate constant of this reaction at $t_1 =10\; min$, is $10^{-2} \;min^{-1}$. What is the rate constant (in $min^{-1}$) at $t_2 = 20 $ minutes ?

Question

( A ) $2 \times 10^{-2}$
( B ) $5 \times 10^{-3}$
( C ) $10^{-2}$
( D ) $0.1$